Ninjago | All seasons

Since Lord Garmadon’s disappearance from the Underworld, NINJAGO Island has been at peace, but the young ninja have grown lazy. While Garmadon lurks in the shadows, waiting for the right moment to strike, the ninja meet his young son, Lloyd, who carelessly unleashes a fearsome new enemy upon NINJAGO Island – the ancient tribes of the Serpentine. The leader of the Serpentine, Pythor, hatches an evil plan to bring back the legendary, all-consuming snake, the Great Devourer. In the Monastery of Spinjitzu, Sensei Wu is interrupted from his meditation by the sound of the ninja fighting. As the cries of battle continue, he enters the training yard only to find it deserted. Wu follows the shouting into the living room only to find them all playing video games and eating pizza. Just as they are about to perform a special attack, Wu unplugs the TV and implores the ninja to start training again to prepare for his brother's return to Ninjago, as ever since Lord Garmadon has escaped, they have done nothing but waste time. Jay complains that peace is boring as they have no one to fight but Sensei Wu lectures the four on "not putting off until tomorrow what can be done today," saying that the four have not yet reached their full potential. Cole then uses the Scythe of Quakes to plug the TV in and the ninja resume their game as Zane assures their master that they will be ready when Lord Garmadon returns.

Their meeting is interrupted by Nya, proclaiming that Lord Garmadon was spotted in Jamanakai Village, sending the ninja into a state of panic. They rush down to the pen where their dragons are kept though have great difficulty mounting due to how out of shape they are. As they eventually take off, Nya question whether they will ever unlock their true potential, but Wu assures her they will in time.

As the ninja fly towards Jamanakai Village, they reflect on what their master has just told them and decide to race to the village. They arrive on their dragons to stop Lord Garmadon, only to find the sighting to be his son, Lloyd Garmadon, who has escaped Darkley's Boarding School for Bad Boys again. Lloyd tries to terrorize the village and rob them of their candy, threatening to release the Serpentine on the villagers, but is instead pelted with fruit and vegetables. The ninja hung him on a sign, amusing the villagers before teasingly eating their paid candy in front of him. Before returning to the Monastery, Kai discovers he has accidentally taken Master Wu's bag in the rush, and finds a scroll that tells of the prophecy of the Green Ninja.

None of the ninja are able to contain their excitement, boasting to the others that himself will become the Green Ninja. All consumed by selfishness, they try to hold a tournament to find who is the best of them all and thus become the Green Ninja. Unfortunately, the idea backfires when Kai's sword starts an elemental fire that cannot be put out. Zane attempts to freeze the fire, Jay catches fire, and Cole hits the flames with his Scythe. Sensei Wu arrives and uses the Shurikens of Ice to stop the fire, before explaining the ninja must agree to continue their path to unlocking their potential before any of them will become the Green Ninja. The hypnotized villagers. Meanwhile, Lloyd wanders the frozen wastelands of Ninjago, upset that his plans have gone awry. Mistakenly, he uncovers an ancient tomb containing a tribe of the real Serpentine known as Hypnobrai. Slithraa attempts to hypnotize Lloyd, but he ducks out of the way, and the General is met by his own reflection in an ice stalagmite, accidentally hypnotizing himself in the process. The tribe is now under Lloyd's control, who sends them to steal all the candy in Jamanakai. The Hypnobrai use their power to hypnotize the villagers, bringing more power to Lloyd.

Sensei Wu senses the presence of the Serpentine with his spirit smoke and quickly alerts the ninja, who rush to the village and are able to defeat the Hypnobrai, forcing them to retreat. However, Skales, the second-in-command of the tribe, hypnotizes Cole before leaving town, forming a scheme to destroy the ninja for revenge. After stealing the Hypnobrai Staff, Nya uses the anti-venom inside it to cure the villagers, but Cole remains under Skales's influence, unbeknownst to the ninja or to himself. At the Monastery of Spinjitzu, Sensei Wu is meditating when he hears voices from outside; to his pleasant surprise, the ninja are busy training instead of playing video games. When Zane uses his Spinjitzu to freeze the entire training course, the other three ninja talk to Wu about their icy comrade's strange behaviors. Wu explains that Zane is a brother to them, and like all brothers, he is different. Soon, the Mailman comes by with letters and packages for all of the ninja except Zane. Jay asks Zane why he never receives any letters from his parents, and Zane sadly says he has been an orphan all his life and never knew his family.

Meanwhile, in the Wildwood Forest, the Hypnobrai are building a treehouse fortress from where Lloyd plans to rule Ninjago. Atop the fortress, Skales is using Cole - unknowingly hypnotized during his previous encounter with the Serpentine -to spy on the ninja, noting that the Hypnobrai staff is in the Monastery of Spinjitzu. Slithraa rebukes his second-in-command for slacking off, but Skales retorts that they should focus on retrieving their staff from the ninja.

At the Monastery, the ninja are enjoying their dinner. Zane walks into the dining room with a roasted turkey and places it on the table, and the others burst into laughter when they notice that he is wearing a flowered pink apron. Zane is confused as to why they find it so funny. Cole tries to make Zane laugh by tossing a plate of shrimp at Kai's face, resulting in a large food fight.

Later that night, when Zane goes outside to take out the trash from dinner, he finds a Falcon that mimics his every move and decides to follow it. He soon discovers Lloyd's treehouse and leads the others to it the next day. After analyzing the structure, Kai thinks that if they sever the ropes holding up the fort, it will fall apart. The plan almost succeeds, but Skales uses Cole to fight the ninja and nearly bring the fort down with them on it. Sensei and Nya arrive just in time on Flame, while Sensei plays the Sacred Flute that breaks Cole's spell.

After rescuing them and destroying the fortress, Sensei Wu explains the flute is as old as the Serpentine themselves and will play a large role in the Serpentine's downfall. Upon returning to the Monastery, they find the entire building demolished and burned to a crisp by the Serpentine, who have stolen their staff back. The ninja berate Zane for causing the destruction of their home and he flies away with Shard.

Back at the Hypnobrai Tomb, a captive Lloyd tells Slithraa to do something about Skales, prompting the General to demand his staff back from the Warrior. However, Skales refuses to return the staff, challenging Slithraa to a Slither Pit for command of the tribe. Mezmo acts as the overseer for the match, and Lloyd is tied to an icicle to keep him from getting away. Unnoticed by the Hypnobrai, the would-be evil overlord manages to snatch a map from a nearby crevice in the process.

Unfortunately for Lloyd, Skales matches Slithraa exactly, even interrupting his hypnosis attempt. When the General uses a large ice shield to block the Warrior's attacks, Skales mesmerizes Slithraa with odd body movements before striking down his opponent with a powerful flying kick. As Rattla identifies the attack as a "Fang-Kwon-Do" technique, Lloyd demands that Slithraa get up, but the General can take no more and passes out.

Mezmo declares Skales the winner and hands him the Hypnobrai Staff. Upon grasping it, Skales' legs begin to merge and lengthen into a tail while Slithraa's tail shrinks into a pair of legs. The other Hypnobrai chant the name of their new General as Skales tells Slithraa to obey him from now on; when Slithraa pledges his allegiance, Skales banishes Lloyd from the top In the mountains, the ninja attempt to keep their spirits up, despite their minimal food and shelter. Just as Jay laments the loss of Zane, the Ninja of Ice returns, telling the others that he has something to show them. As they arrive in the Sea of Sand, Zane explains he was following the Falcon, which led him to a ship known as Destiny's Bounty. The ninja rejoice and Sensei Wu promises Zane that they will help him find his family, but Zane tells his mentor that they don't have to, as they are his family. They later engage in another food fight, unaware that Lloyd passes by after seeing them. The ninja are woken early in the morning by Sensei Wu clanging a gong. To their dismay, the old master wants them up and working at the crack of dawn, in order to clean up their new home, the Destiny's Bounty. Although the ninja are reluctant at first, they soon realize that they can use their Spinjitzu to speed up the process. By the time Sensei Wu and Nya return to the ship, it is much cleaner.

Suddenly, the ninja receive a surprise visit from Jay's parents, Ed and Edna. Although the others quickly take a shine to the Blue Ninja's parents, Jay rapidly grows frustrated: Ed and Edna reveal several embarrassing facts about his past, gush over Nya as the perfect match for their son, and ask Jay to visit their junkyard sometime. After several hours of this, Jay ushers his parents back to their junkyard, hastily promising to visit them soon. As the jalopy rolls down the road, Ed sadly tells Edna that their son is growing past the need for parents. Meanwhile, Lloyd is wandering through an eerie graveyard, deep within Wildwood Forest. Planning vengeance on the treacherous Hypnobrai tribe, he is using the Map of Dens to seek out the Fangpyre, reasoning that the best way to beat a tribe of Serpentine is with another tribe of Serpentine. The prospect of vengeance is all that supports his nerves as he reaches the center of the graveyard and opens the Fangpyre Tomb. As the snakes within surround him, Lloyd suddenly finds himself face-to-face with Fangtom, the two-headed Fangpyre General. Lloyd offers an alliance against the Hypnobrai and the ninja, which Fangtom likes the sound of. However, he notes that his army will need reinforcements to battle the Hypnobrai, prompting Lloyd to ask what the General has in mind.

That night, Ed and Edna return to their junkyard, still melancholy about the icy reception they received from Jay. As Ed goes to work on some of the vehicles lying around, the lights go out and dark shapes rush through the shadows. Suddenly, the Fangpyre emerge, with Lloyd and Fangtom looking down on Ed and Edna from atop their trailer. Fangtom bids his forces to "have at it," and the snakes begin biting Ed's scrapped vehicles, transforming them into bio-mechanical Serpentine vehicles. Ed and Edna watch in horror as Fangtom explains his intent to reinforce his army, before revealing that the Fangpyre can infect people just as easily. Clinging to each other in fright, Ed and Edna can only scream as the red-scaled snakes surround them.

The next day, the ninja prod Jay into keeping his promise and visiting his parents. However, their dragons are lethargic and uncooperative, which Master Wu identifies as the beginning of their molt. To the ninja's dismay, they are forced to release their dragons so they can complete their molts at the Spirit Coves. After seeing the beasts off, the ninja, Nya, and Sensei Wu head to Ed & Edna's Scrap N Junk on foot.

When they arrive, the place is quiet—Jay is worried since his parents are "never quiet." A quick search reveals Ed and Edna bound and gagged inside an old refrigerator—more shockingly still, they have developed small fangs, forked tongues, and a noticeable hiss to their voices. Sensei Wu immediately identifies their condition as the result of Fangpyre venom—the only way to cure them is to get the anti-venom from the staff. On cue, a Fangpyre-infected wrecking ball appears, along with a horde of Fangpyre and Lloyd.

The ninja engage the snakes in battle, dodging the attacks of the wrecking ball in the process. With Nya covering him, Sensei Wu uses the Sacred Flute against several Fangpyre, only for Lloyd to counter with loud music from a Serpentine boombox. Sensei Wu irritably chides Lloyd for supporting the wrong side, but the would-be evil overlord turns up the volume and claims not to hear his uncle. Luckily, Edna manages to save Sensei Wu from a Fangpyre scout with a well-timed frying pan to the back of the head.

Elsewhere in the scrapyard, the ninja pursue a trio of Fangpyre around a pile of junk. Unfortunately, this allows the snakes to bite the Mechanical Ninja—which Ed claims it was made in Jay's honor—and transform it into a giant battle robot. Unable to compete with such a large foe, Jay commandeers the Fangpyre's wrecking ball, using it to bring down the robot. With the battle turning against his allies, Lloyd leads the Fangpyre in a retreat, personally joining Fangtom on a platform carried by a Rattlercopter.

With the Fangpyre General airborne, the ninja despair of ever curing Ed and Edna, but Sensei Wu reveals that their Golden Weapons have the answer. By focusing on thoughts of taking flight, the ninja manage to transform their weapons into sleek vehicles, allowing them to pursue the snakes. Using his new Storm Glider, Jay manages to steal the Fangpyre Staff from the Rattlercopter, only for all four ninja to lose their focus and dispel their vehicles. With their transportation gone and the rest of the Fangpyre forces up ahead, the ninja and their allies quickly retreat to the Destiny's Bounty.

As Nya creates tea from the staff's anti-venom and cures Ed and Edna with it, Jay desperately tries to activate the "defense system" he installed into the ship. As the Fangpyre close in, Ed takes a look at the controls and repairs it, allowing Jay to activate the ship's new flight modifications. With a roar of engines, the Destiny's Bounty soars out of the desert, leaving Lloyd coughing on the dust stirred up by its flight. Unfortunately, Nya accidentally drops the Fangpyre Staff out of the back of the ship, allowing Fangtom to retrieve it after it knocks out one of his soldiers.

Aboard the Destiny's Bounty, Jay sheepishly thanks Ed for helping with the flight system, apologizing for his earlier rudeness. Ed and Edna apologize in turn for being too overbearing and excited, allowing parents and son to reconcile on the best of terms. Zane has a dream of the Falcon perched on some power lines, telling him to wake up. Zane bumps his head on the bed above him as he awakens, greeting Sensei Wu and Nya who tell him that they are not safe with Lloyd and the Serpentine on the loose. Zane questions where the others are and Master Wu informs him that they are training on the upper deck.

When he arrives on the deck, he notices the Falcon and begins talking to it. The Falcon then flies off, and as the shadow of Lord Garmadon approaches, Zane turns around and questions him. Lord Garmadon tells him that he has returned to retrieve the Golden Weapons, pulling out two silver katanas and rushing into battle.

After Zane dodges him, Lord Garmadon demands the Shurikens of Ice, throwing him into a trash heap upon refusal. Lord Garmadon cuts a rope holding a heavy crate, but before it could fall on Zane, the Green Ninja appears, lifting the box and throwing it overboard. The Green Ninja immediately engages in a battle against Lord Garmadon, using the Nunchucks of Lightning to defeat him. Zane wonders who the Green Ninja is as the Falcon perches himself atop the mysterious figure's arm, his hand and eyes in flames, and the entire deck covered with falcons.

Zane then awakens again, hitting his head as he did in his dream. However, he is unconvinced that he is awake and believes he is still dreaming. Cole decides to hit him over the head with a pillow to convince him, causing the ninja to laugh.

Out on the upper deck, Sensei Wu commands the ninja to warm up with stretches while Zane tells the ninja of his dream. The excitement of the Green Ninja's appearance in Zane's dream makes the four do poorly in their warm-ups, and Sensei Wu punishes them by ordering them to train the rest of the day until they can answer the riddle, "What is the best way to defeat an enemy?" They begin training but are quickly distracted again as Zane tells more of his dream.

Meanwhile, Lloyd travels through the snow with the Fangpyre in order to attack the Hypnobrai. Upon seeing Skales, Fangtom happily greets him and the two begin chatting as they had been allies in the past. Lloyd questions why they are not fighting and Fangtom explains that there is no reason to go to war if the Hypnobrai's new General is Skales. Skales then mentions that if he had released any of the other tribes he would have easily gone to war, and as the two Generals discuss what they will do with Lloyd, Lloyd is quick to escape the scene.

At the Destiny's Bounty, Zane finishes telling the others of his dream and the ninja immediately argue over which of them is the Green Ninja. Sensei Wu interrupts and comments that because they are not training, they must have figured out the answer to the riddle. None of the ninja can answer the question, so Kai offers "training" as the solution to the riddle. Sensei Wu tells them they are wrong, and reminds the four they must learn to focus and keep their minds sharp before retreating back below deck. The ninja decide to come together and figure out the correct answer between them.

As Lloyd traverses through the Sea of Sand with the Map of Dens, he stumbles upon the Anacondrai Tomb and quickly rushes over to its doors. He navigates through using a flashlight, spotting the skeletal remains of the Anacondrai tribe before being startled by Pythor. Pythor apologizes for scaring Lloyd, but Lloyd only questions what happened to the rest of his tribe, to which Pythor explains that they starved without food. The two introduce themselves, and after realizing how alone they both are, Lloyd propositions Pythor to be his henchman. Upon seeing Lloyd is in possession of the Map of Dens the General agrees and the two start their friendship.

Later, Pythor and Lloyd cause trouble in Jamanakai Village and raid the village's supply of candy, returning to the Anacondrai Tomb once they are done. While the two rest with their spoils, Pythor asks Lloyd why he has no friends. Lloyd at first lies to Pythor saying that he ran away from Darkley's Boarding School for Bad Boys, but reveals moments later that he instead was kicked out of the school for lacking the amoral ambition to be one of tomorrow's masterminds. Pythor then suggests they head to the school the next morning to get revenge on both the students as well as the ninja.

Back at the Destiny's Bounty, the ninja confidently tell Sensei Wu that the answer to the riddle is "teamwork," but Sensei Wu is quick to inform them that their answer is incorrect. As they leave the alarm goes off, and upon arriving at the bridge Nya tells them that there is Serpentine activity at Darkley's.

At Darkley's Boarding School for Bad Boys, Lloyd and Pythor tie up the students in their classroom. As Lloyd and Pythor are on the lookout in preparation for the ninja, Pythor announces that all the traps are ready.

While the ninja contemplates methods of infiltrating the building, they decide to try Jay's idea of the four holding onto the ship's anchor as Nya drops it into the school. They end up on the lowest floor of the building, and upon noticing the tied up students, Cole frees them by cutting the rope with his Scythe. Afterward, they spot Lloyd on the roof through the hole they created, each ninja taking their own route to the top. However, they are all stopped by the traps Pythor had set up, except for Jay, who quickly pursues Pythor as he escapes to Lloyd's location. Upon being confronted by Jay, Pythor takes the opportunity to snatch the Map of Dens from Lloyd's pocket and disappear from sight. As the Destiny's Bounty flies down to the roof's level, Jay grabs Lloyd to bring him to the ship while the other ninja suggests punishments for his behavior.

Later in the night, Sensei Wu puts Lloyd to bed after reading him a bedtime story from a book called Jack the Rabbit. As the ninja complain to Sensei Wu about a lack of punishment for his nephew, Sensei Wu remembers the riddle from earlier and asks them if they had solved it yet, though they still do not know. Sensei Wu then announces that the best way to defeat an enemy is to make them your friend. It was then the ninja realized that Wu is trying to put Lloyd on a better path. Aboard the Destiny's Bounty, Lloyd informs Kai that Cole beat his high score on Fist to Face 2, angering Kai when he confirms the information. Inside the dining room, Cole prepares Violet Berry Soup, only to find that it tastes horrible; at that moment Lloyd walks by and claims that he saw Jay messing with the soup. On the deck, Jay activates his sparring bot for training, but it begins malfunctioning—Lloyd says that he saw Zane tampering with it before leaving Jay to deal with the aggressive robot. Later, Zane walks onto the deck to grab his laundry when Lloyd passes by, mentioning that Kai had washed his ninja suit with Zane's before walking off. Zane then notices that his white ninja suit has now turned bright pink.

As all four ninja meet up inside the Bounty to argue, Sensei Wu comes in to reveal that Lloyd was responsible for their troubles, telling them that he had purposely ordered Lloyd to sabotage them to teach them about the destructive power of rumors. When Cole puts the lesson into question, Sensei Wu admits that he had misplaced his lesson book, only to find that Lloyd had stolen it. Through a speaker in the room, Nya alerts the ninja to come to the bridge. There, she informs the ninja that Pythor is on his way to the last two Serpentine tombs, and Sensei Wu immediately commands Kai and Jay to head out to the Venomari Tomb, while assigning Cole and Zane the Constrictai Tomb. Lloyd wants to come along, but Wu puts him to work fixing the damage from his pranks.

Cole and Zane travel to The Mountain Of A Million Steps on their Tread Assault and Snowmobile, but upon arriving, Cole notes that their vehicles will not be able to traverse the rest of the way. When Zane points out that they are pressed for time, Cole decides to take a shortcut by climbing the rest of the way up, carrying Zane on his back. They then arrive at the top of the mountain and take a rope down the entrance to the Constrictai Tomb.

Inside, Zane begins reading over the ancient markings on the tomb walls, translating them into a story of the five Serpentine tribes uniting and the four Fangblades. As Zane and Cole discuss what it could mean, they are interrupted by the ground under them shifting. Skalidor pops out of the earth behind them, wrapping his tail around Zane. Cole is quick to rush in, using his Scythe to cause an earthquake and forcing Skalidor to retreat underground. Cole orders Zane to escape, but he is hesitant when Cole is dragged under the ground and thrown back to the surface. Cole uses the Sacred Flute in an attempt to fend him off, however, upon playing it Skalidor resurfaces and constricts Cole with his long tail. Zane rushes in to grab the Sacred Flute and begins playing, but Skalidor cuts it short by using his tail to choke him. Zane barely manages to get out enough breath to finish the tune, causing Skalidor to release both of them as he holds his head in pain. Cole then takes the opportunity to hit Skalidor over the head with his Scythe and knocks him out cold. Zane and Cole decide that Kai and Jay are likely walking into a trap as well, and the two quickly exit the tomb to aid them.

On their Blade Cycle and Storm Fighter, Kai and Jay arrive at the Toxic Bogs. They stop to observe the acid lakes, realizing that they must travel the rest of the way by swinging across the many vines. The two find the Venomari Tomb's entrance, but when Jay opens it they find the tomb is already empty. Kai leaves Jay's side, who is playing with the echoes by the entrance, as he investigates the Toxic Bogs, only to encounter a purple bog frog, who jumps on top of Spitta, who was hiding inside an acid lake. Spitta sprays venom into his eyes, and as Kai begins hallucinating, he calls to Jay for help. The Venomari and Constrictai all come out of the acid lakes, cornering Kai as he starts to see the Serpentine as Gingerbread men and Christmas elves. After Jay finally rushes to Kai's side, Cole and Zane both arrive as backup. However, Pythor jumps out of the empty Venomari Tomb, stealing the Sacred Flute away when Zane attempts to use it against him. As the Serpentine close in on the ninja, they step back onto a sinking log in the acid lake. Before the log could completely sink and erode, a rope suddenly appears before them and allows the ninja to climb to safety. A mysterious figure known as Samurai X flies down, sending out a large net toward the Serpentine which forces them to retreat. The figure inside the large mech jumps out, and the ninja approach the Samurai to show their gratitude. Kai thought the Samurai was Santa due to still being under the influence of the Venomari venom. However, the Samurai sprays them with a gas that causes all four ninja to lose consciousness and fall to the ground, to which the Samurai gets back into the Samurai Mech and flies off. Above the unconscious ninja, the Destiny's Bounty flies overhead, shining a light onto them.

Later that night, the ninja are conscious again inside the dining room of the Destiny's Bounty, each discussing the Samurai. Cole tells the others to concentrate on the Serpentine instead of the Samurai, and while they fearfully speak of the Great Devourer, Zane informs Sensei Wu that Pythor stole the Sacred Flute. Lloyd blames himself for releasing the first three tribes, but Sensei Wu reminds him that they can only change the future, not the past. An alarm goes off and the ninja run to the bridge, the monitor showing Serpentine activity in Ninjago City.

The ninja jump off the Destiny's Bounty and Zane and Cole use their vehicles to safely land in Ninjago City, while Kai, who is still experiencing the effects of the Venomari venom, hitches a ride on Jay's. After looking around, Zane mentions that they are supposed to be standing in the middle of a massive Serpentine gathering, giving them the idea of looking through the manhole in the sidewalk.

Meanwhile, all five tribes gather in the sewer, Skales telling Pythor that he will need more than words to persuade them. While Pythor presents to the large group of Serpentine a speech, the ninja sneak around making bad comments to get them riled up. The Serpentine begin to lose focus on Pythor, and Skales spots the intruders, sending groups of Serpentine after them. Cole, Kai, and Jay are quickly captured, leaving Zane to flee on his own. However, he uses his pink suit to his advantage and camouflages himself by a pink poster, making the small group of Constrictai being unable to see him.

The Serpentine continue fighting among themselves as Skales tells Pythor that he has captured three of the ninja. Zane swings in above the crowd on a rope, knocking Skales and Pythor over to save his teammates. All four ninja swing above the crowd in order to escape, making a run for it upon landing. The Serpentine follow and Zane freezes over the hallway with his Shurikens, giving the ninja the opportunity to jump aboard Zane's Snowmobile. The group of Serpentine start slipping on the ice, allowing the ninja to escape.

Back at the Destiny's Bounty, Cole begins talking about their day, noting that they had used the destructive power of rumors to their advantage. As they continue the discussion, Lloyd comes into the room with Zane's ninja suit, announcing that the color is returned to normal after twenty loads. As an apology to Cole, Lloyd hands him a can of nuts, but Cole is skeptical about opening it and goes to the fridge instead, where dozens of rubber snakes fly out at him. Skales and Pythor are busy digging in the Sea of Sand. Pythor is looking for the Lost City of Ouroboros, said to be the prison of the Great Devourer. Skales is skeptical, insisting that uniting the Serpentine is impossible, but Pythor soon finds a switch under the sand and pulls it, revealing the city.

Aboard the Destiny's Bounty, Lloyd Garmadon is discussing with the ninja how he would attack a Serpentine. The ninja correct him excessively, and Lloyd asks Sensei Wu how he would attack a Serpentine. Sensei Wu responds with an ancient proverb and then tells the ninja that he has new suits for them. The ninja are happy to receive their ZX suits and are ready for a test run. Nya reports that Serpentine are terrorizing the Mega Monster Amusement Park. The ninja are more than ready to reply to the call.

Upon arriving, however, the ninja find that the Serpentine threat has been taken care of. Nya, who was at the scene, mentions to the ninja that a figure known as Samurai X had already arrived and handled the problem. The ninja are perplexed, and Master Wu, who comes out of a gift shop with cotton candy, tells them that the Samurai may help them better themselves through healthy competition. Interpreting their Master's advice as a hint that whoever catches the Samurai first deserves to be the Green Ninja, the ninja set off to find the mysterious warrior.

Kai, who is patrolling Ninjago City, drops Lloyd off at the Kiddie Arcade, much to Lloyd's protest. After Kai speeds off, Lloyd overhears the Serpentine preparing to head to the Lost City of Ouroboros. Lloyd dons a Serpentine disguise and follows the snakes on to a bus to the city. After a long drive, they reach the city, which is resting in the Sea of Sand. They all pile into a colosseum, where Pythor is announcing a Slither Pit. He tells the Serpentine that if he beats all of the Generals at once, he wants their complete, undivided loyalty. Skales, who is secretly supporting Pythor, gives him the stolen Sacred Flute to use against the Generals during the fight while he wears earplugs and pretends to moan in agony. Once Pythor emerges from the Slither Pit as the victor, he demands the Serpentine to bow to him. When Lloyd attempts to bow as well, however, he accidentally drops a part of his disguise, revealing himself to the tribes.

The ninja, back at the Destiny's Bounty, are complaining about their failed attempts to try and capture the Samurai. Sensei Wu comes in, noting that Lloyd is not present. Kai tries to claim that Cole was supposed to pick him up, but Cole places the blame on Jay. Sensei Wu, who is utterly afraid of what might have become of his nephew, tells the ninja to go find him.

They head over to the Arcade Kai had dropped Lloyd off at, and watch security camera footage from outside the building, spotting Lloyd putting on a Serpentine costume. Upon discovering his footprints outside, the ninja use their vehicles and begin to track down Lloyd. They come upon the gates of The Lost City of Ouroboros and slip past the guards. They come upon the border of the colosseum and spot Lloyd in a cage beside Pythor, but when they rush in to save him, they trigger a trap and are locked inside a cage as well, dropping their Golden Weapons. The ninja are led to the center of the colosseum, and Pythor announces another Slither Pit. Just then, Samurai X is also led out. The duel begins and the Samurai throws projectile weapons at them, but they dodge most of them. Pythor makes the game more interesting by tilting the stage and revealing spikes. As the ninja hang onto Samurai X's exo-suit, he tells them to keep the charade up and begins flying. However, the suit is too heavy and he ejects himself from the mech, allowing the ninja to escape safely, much to their anger.

As the exo-suit falls to the desert ground, Zane, Jay, and Cole fall as well, with the exception of Kai, who fell in a different direction. Kai spots Samurai X without his mask, revealing himself to be Nya. Nya explains to Kai that she was tired of how much focus was being placed on the ninja and she wanted to help out in her own way. Kai promises he won't tell the others, and Nya hands Kai the Golden Weapons she secured.

Back at the Destiny's Bounty, Kai explains to his teammates that Samurai X just handed him the Golden Weapons and left. As Sensei Wu leaves the ninja to go to bed, he hands Nya one of the Samurai's weapons, telling her knowingly that "iron sharpens iron, and sibling sharpens sibling," expanding upon what he had told the ninja earlier on. After Zane breaks his previous record for holding his breath underwater, the ninja wonder if they have reached their full potential. They seek out Sensei Wu, who tells them that they have only reached their physical peak; their true potential requires mental enlightenment as well.

Sensei Wu recounts a story from his childhood: One day, while he and his brother were playing outside, Wu lost his katana. Knowing their father would not be pleased, Garmadon sought to find it since Wu refused to. Garmadon found the katana eventually, but upon reaching down to pick it up, he was bitten by a snake known as the Great Devourer, kickstarting his descent into darkness. After telling his story, Sensei Wu declares that he is going on a journey by himself, and the ninja drop him off at a mountain.

Later on, the ninja travel to Jamanakai Village with Nya to post signs about the missing Fangblades. As Zane is posting signs, he sees the Falcon. He and the ninja follow it, but soon the others are too tired to go on. Zane proceeds into a frosted forest when the Falcon suddenly drops to the snowy ground.

Zane picks it up and is shocked to see that the bird is actually mechanical. He is then ambushed by a large robot, but quickly destroys it and notices that the Falcon and the robot have the same mysterious symbol printed on them. Zane proceeds into a hollow tree and discovers a workshop inside. While searching through the building, he finds a blueprint and drops to his knees, crying out in horror.

Meanwhile, Sensei Wu enters Mystake's Tea Shop and requests Traveler's Tea. The owner claims not to have heard of it, but upon receiving payment, brings out a pot and warns Master Wu that those who drink the tea do not return. Back in the forest, the ninja find Zane inside the tree and ask why he is distressed. Zane suddenly opens up his torso, revealing that he is actually a robot. The ninja assure him that he is still their brother, but Zane, still quite shaken by the revelation, asks to be left alone. Kai, Jay, and Cole leave the workshop, but are soon attacked by Treehorns.

Inside the workshop, Zane takes another look at his blueprints and, upon realizing he has a memory switch, flips it on. This causes him to remember being built by his father, Dr. Julien, and all the different things he taught him over the years. He also recalls that his father, just before dying, turned off his memory switch to save him the pain of heartbreak. Zane sheds a tear for his father before rushing out to help his friends.

The ninja defeat the Treehorns, but things take a turn for the worse when their Queen arrives. Realizing who he is, Zane overcomes the obstacles of his heart and unlocks his True Potential. With his newfound powers, Zane freezes the Queen and the other Treehorns retreat. The other ninja commend Zane for unlocking his True Potential and Zane proclaims that they are going to find Pythor.

Meanwhile, Pythor is still desperately trying to unite the snake tribes by solving a riddle: "When the five fangs unite as one, the path toward the Devourer has begun." The other leaders begin to doubt Pythor, saying that snakes will begin to ask questions. Just then, Acidicus and Skalidor get into a tussle with one another, and their staffs are tossed aside. The venom from their staffs drips onto the floor, then Pythor realizes something. He gathers all five staffs and puts them in a leaning formation over the table, Pythor realizes it's been right in front of them the whole time. "When the five fangs unite as one, the path toward the Devourer has begun." The riddle wasn't talking about of the five tribes, it was the venom in the five Staffs. As Pythor slides a scrap of paper underneath. The venom drips onto the paper, revealing a map that shows the locations of the four Fangblades. Having solved the riddle, Pythor and the others rejoice.

On a tall mountain, Sensei Wu is shown to be meditating before pouring the Traveler's Tea in a circle around his campfire. A vortex then erupts, and he steps into it. He reappears in another realm, where he is greeted by his brother, Lord Garmadon. The villagers have unearthed a Fangpyre skeleton and Nya is experimenting on it to try and reverse the effects of a Fangpyre bite without the anti-venom in the staff. She observes that it is possible to reverse the effects by raising the victim's heart rate. Jay nervously asks Nya out on a date, which she accepts. After she leaves, Jay dances around the room in celebration but accidentally pricks his finger on the Fangpyre skeleton's fang. When he leaves, a drop of venom falls from the fang to the floor, a fly drinks it rapidly transforming into a fangpyre-fly.

In the Realm of Madness, Sensei Wu tries to tell Lord Garmadon about Lloyd having been captured, but Garmadon does not listen. They engage in a fight that culminates in Garmadon summoning his mud monsters to defeat Wu. As the mud monsters envelop him, Wu tells Garmadon that Lloyd is in danger. Shocked at this news, Garmadon saves him and Wu explains what Lloyd has done. Garmadon agrees to go back to Ninjago to help Lloyd. Wu tells him that he is out of Traveler's Tea, so Garmadon informs him that the only way to get back to Ninjago is to climb the Mountain of Madness.

Elsewhere, Pythor and the Serpentine head off to Mega Monster Amusement Park to dig up the first Silver Fangblade. The ninja find out that the Serpentine are at the amusement park, so Jay arranges for him and Nya to have their date there so he can fight the Serpentine if necessary. As they enjoy their dinner in the park's restaurant, Jay finds out he is slowly transforming into a snake due to the bite and rushes to the restroom to check himself over. Meanwhile, the ninja investigate a ghost-themed ride and find that the Serpentine have already dug up the first Fangblade. Zane accidentally freezes the three of them while in NRG mode, allowing the Serpentine to escape.

When Jay comes out of the restroom, he is surprised to find that Nya is gone, having assumed her secret identity as Samurai X. The restaurant patrons see Jay and attack him, believing him to be a snake. Jay runs back into the restroom and comes out with a scarf concealing his face so he can escape. Meanwhile, the Serpentine battle Samurai X and eventually find out that she is really Nya. They trap her in a roller coaster car and send her careening down the track, which has a large gap in the middle. Jay tries to rescue her, but his scarf blows off, revealing his reptilian appearance. When they rapidly approach their doom (a break in the tracks with a ring of fire), Nya tells Jay that he does not have to pretend to be anything he's not to impress her, as she likes him exactly for how he is. She then kisses Jay, raising his heart rate and turning back into a human. Inches away from the break, Nya utters her last words to Jay "You are the best you". Feeling inspired by Nya's words, Jay unlocks his True Potential when he realizes he's free to be himself around his friends, especially Nya, and saves them with his increased strength, teleportation, and ability to fly.

Afterwards, the ninja and Nya regroup and Cole announces that the Serpentine have the first Fangblade. They wonder where Sensei Wu is and what he is doing. Meanwhile, Lord Garmadon and Sensei Wu have reached the Mountain of Madness and prepare for their journey back to Ninjago. Having the map to the four Fangblades, the Serpentine arrive at a pyramid. While they navigate through the ancient tunnels, Pythor comes to a sudden halt. The Anacondrai General taps his Staff to the stone flooring, the weak ground ahead of him crumbling. Pythor then orders Skales to release Lloyd from his chains. Pythor informs Lloyd that he has only released him temporarily to maneuver himself around the sinkhole, an act that only Lloyd could perform, thanks to his small stature. Lloyd carefully walks around the hole that Pythor created, afterward running as the floor starts falling apart with every step. When he finally reaches solid ground, the spiked ceiling begins lowering itself over him, which causes him to run through and accidentally activate another booby trap. Arrows shoot through the walls at Lloyd, who narrowly escaped, unharmed. The pedestal with the Fangblade comes into view, though Lloyd stumbles and hits a pole that supports the ceiling. The collapsing ceiling forces him to rush forward. When he reaches the pedestal, he realizes that the Fangblade is missing, calling back to the Serpentine to tell them of the object's absence.

In Destiny's Bounty, the ninja start discussing the location of the second Fangblade. Cole announces that he remembers where he recognizes the Fangblade from, leaving the room and returning with a picture book. Jay eagerly takes the book from him and shows it to the rest of the team. Cole tells them of an annual competition that awards the winner the Blade Cup, saying that his father won it multiple times before. Having perked his interest, Zane comments that Cole has never spoken of his father being an accomplished athlete. When questioned about what sport, Cole tells him that his father is a Blacksmith. Kai finds it odd that there would be a competition involving the occupation, Cole correcting himself by stating that his dad is a Royal Blacksmith. The Earth Ninja continues, saying that the Fangblade was made into the Blade Cup by a fellow named Clutch Powers. Zane asks who is currently in possession of the trophy, Cole sorrowfully admitting that he has not spoken to his father in years. He then begins telling a story of how his father wanted his son to follow in his footsteps, but Cole ran away when he was unable to sing or dance, sending letters to his dad and pretending to still be at the Marty Oppenheimer School of Performing Arts. Zane is astonished that his dad is unaware of his current occupation, automatically Cole assuming that his teammates will make fun of him for his story. The ninja assure him otherwise, stating that they must get their act together if they want to reach the second Fangblade in time.

Meanwhile, at the Mountain of Madness, Lord Garmadon and Sensei Wu journey toward the peak of a large hill. Lord Garmadon admits that he was hoping to reach the summit before the moon rose. While they converse about the surrounding terrain, nearby boulders form together to create a group of Craglings. The giant monsters gain on the two brothers, Lord Garmadon and Sensei Wu instinctively drawing their weapons to fight back. As they fend off the beasts, they both perform Spinjitzu in an attempt to defeat the Craglings.

As the Destiny's Bounty flies over Ninjago City, all four ninja jumping off and activating their elemental vehicles in order to land safely. Having dressed in casual attire, Cole tells the other ninja to put their Golden Weapons in a briefcase to complete their disguise. They arrive at Lou's house, Cole happily greeting his father when he opens the door. However, Lou is reluctant to let them in, closing the door on them and ordering his son to use the doorbell. Upon complying, Lou opens the door and invites them inside. There Lou serves them tea, Cole feeling agitated as Lou tells of a story involving his foot injury. As the ninja fabricate a lie about their arrival, Cole comes up with the excuse that his team is writing a research paper and needs information about the Blade Cup. Lou begins rambling about winning the annual Ninjago Talent show, suddenly under the assumption that the actual purpose of their visit is to replace The Royal Blacksmiths since Lou's quartet is unable to perform that year. Overwhelmed by pride, Lou decides to leave the room to write a song about it. Kai then announces that they are entering the competition in order to steal the Blade Cup.

Mezmo and Snike stroll through Ninjago, spotting a poster for the competition. Snike is eager about the singing portion of the competition at first, but Mezmo points out that the Fangblade is in the trophy. Snike then directs his energy toward their discovery, Mezmo declaring that they must alert the other Serpentine.

At Lou's house, the ninja practice a simple dance routine. However, Lou is very critical, even more so than Wu, pointing out the faults in each of their moves except for Zane. Lou decides that they should focus on the routine's grand finale instead. He mentions that they cannot have history repeating itself, Cole retorting that he was only seven when he performed the Triple Tiger Sashay. He elaborates by saying that he attempted said dance move when he was young but failed since it has never been successfully completed.

As the ninja continue their routine outside, Skales and Pythor spy on them through one of the city's manholes. Skales is impressed with their work and grimly feels that they will never obtain the Fangblade. However, Pythor reassures the Hypnobrai General as they retreat back into the sewers.

Back at the Mountain of Madness, Lord Garmadon, and Sensei Wu press on after the Craglings have been defeated. Lord Garmadon informs Sensei Wu that the vortex is just ahead, Sensei Wu commenting that he can still see good in him despite his evil actions.

They arrive at the portal, Lord Garmadon saying that Sensei Wu puts too much trust in him before ruthlessly kicking his brother down toward the whirling vortex below. Sensei Wu barely manages to grab ahold of the landing, quickly telling Lord Garmadon that he only sought him out to save Lloyd. Lord Garmadon states that he will be seeing him on the other side of the vortex, kicking him once more and jumping in himself.

In Jamanakai Village, a portal opens in the sky, sending Sensei Wu and Lord Garmadon flying out.

Meanwhile, in Ninjago City, the ninja are preparing inside the backstage of Concert Hall. However, Jay and Kai begin arguing when they continuously mess up the routine. Cole interrupts by saying that they will be leaving soon after their theft, Jay replying that they should try to win it. Having overheard the conversation, Lou confronts them about it. Cole takes the opportunity to explain to him the situation of having lied to his father for many years, revealing that he is a ninja. He informs Lou that if they do not steal it themselves, the Serpentine will instead. Regardless, Lou is not accepting of his son for wanting to steal the prize, storming out of the room. While the ninja comfort Cole, a group of disguised Serpentine called the Treble Makers appear backstage. Kai hears Pythor's voice from the crowd, peering out from behind the curtains to see the General among the judges. The other judges say that Pythor looks nothing like how he did in the photo, Pythor coming up with an excuse before the voice of the former judge alerts the others of his situation from Pythor's stomach. The other judges gaze in disbelief, Pythor quickly persuading the noisy judge to quiet down.

Kai tells the ninja of the Serpentine, and when Jay finally agrees to steal the Blade Cup, Cole instead decides that they will win it.

The Treble Makers sing on stage, the crowd booing as Pythor gives the performance a perfect ten. The other judges each give it a six, but Pythor intimidates them into flipping their scorecards, now reading nine.

The ninja are called up on stage, though as they linger backstage, Zane confesses to having butterflies in his stomach. They then share a few encouraging words among themselves, going on stage by the name of Spin Harmony. As they dance in perfect sync, Skales orders the Hypnobrai to attack. However, the attack only intensifies their performance, the ninja incorporating defending themselves in their routine. When the Fangpyre join the ambush, Cole then uses the opportunity to perform the Triple Tiger Sashay with success.

Afterward, the judges excitedly give the performance perfect scores, except for Pythor who gives it a zero. However, the judge that Pythor swallowed resurfaces only to draw a one on his scorecard, making it a ten. The ninja are awarded the Blade Cup, though as Cole looks through the crowd, he realizes that his father is nowhere to be seen.

They return backstage, Zane, Jay, and Kai happily talking about their success. Cole gives them the Blade Cup before sadly telling them to go ahead and celebrate without him. Lou then approaches them, proclaiming that he saw the entire performance. Cole gleefully runs up to his father and hugs him, Lou going on that he saw their fight with the Serpentine, then admitting he was wrong to force Cole to be something he was not. Pythor then arrives backstage and pulls off his disguise, ordering two Constrictai Warriors to drop stage lights onto Lou. Cole jumps in before the objects hit Lou, though the lights fall onto the both of them regardless. Pythor snatches the Blade Cup as everyone is occupied in the commotion. The other ninja rush to the pile of stage lights, looking around for any sign of life. They notice that the Scythe of Quakes is glowing from the briefcase, Zane remarking that he has reached his True Potential. With super-strength, Cole lifts the stage lights off of his father; Jay and Zane complimenting him on his new-found powers while Kai complains about being the last to find his. Cole's powers wear off, Lou informing his son that everyone is safe.

The ninja return to Lou's home, Lou hanging up a framed photo of the ninja with the Blade Cup. As the group gazes at the photo, Lou declares that they are all his family, to which everyone pulls in for a hug. During the night, Cole, Zane, and Jay are all outside on the deck of the Destiny's Bounty, each attacking the silhouette of what appears to be Lizaru. In the middle of the battle, Nya shines a light onto them and compliments their training skills, revealing the silhouette to be a training dummy.

Inside the Bounty, Kai secretly wears the Green Ninja suit while he tries out different catch phrases, looking in the mirror to see his teammates watching him from behind as they mockingly laugh at him. Cole is quick to make fun of him for his silly actions and Kai explains to the others that he stumbled upon the suit when he was looking around Sensei Wu's room for any clues of who the Green Ninja could be. Zane reminds him that only the one who is destined to fulfill the role of the Green Ninja is allowed to wear it, to which Kai interrupts him saying that he was desperate to reach his True Potential like the others already had.

The ninja then abruptly stop their conversation when they hear the voice of Sensei Wu, who returned home from his journey, and the ninja (with the exception of Kai who needs to put the green suit back) rush out to greet him. Jay excitedly tells Sensei Wu of everything he missed, though when Kai comes out telling his Sensei that he is relieved of his safe return, Lord Garmadon reveals himself from behind his brother. Kai's first instinct is to rush into battle, whereas Zane throws himself in front of Sensei Wu to protect him. Wu immediately orders Kai to stop, informing his students that Lord Garmadon will be staying with them for the purpose of rescuing Lloyd. Disapproving of this, the ninja tried to argue, but Sensei Wu, not wanting to hear on what they are saying, just silences them. Lord Garmadon assures them that his brother's words are true, and Wu declares to both the ninja and Nya "from here on out, you all will obey me and you will respect my brother", to which they begrudgingly agree.

At dawn, everyone meets up at the bridge to discuss the Fangblades. Sensei Wu dismisses Kai and Nya to prepare the deck and check the anchor in order to be ready for Serpentine activity. Afterward, as Jay decides to tell Sensei Wu the full story of the events during his absence, Kai admits to Nya that he does not trust Lord Garmadon. While they converse about the subject, Kai convinces himself that he will unlock his True Potential if he can stand up to Lord Garmadon.

During the Dark Lord's stay, he surprises the ninja by casually filing his teeth alongside them. Then at the dining room, Kai watches in distrust as Lord Garmadon eats a dish that Kai identifies as condensed evil. Later, Jay and Nya are relaxing in the video game room while they watch a romantic movie together, only for Lord Garmadon to disrupt it by changing the channel, to their dismay. Garmadon is later seen "sunbathing" on the deck during a thunderstorm, and interrupting the ninja's sleep the following night with electricity.

Lord Garmadon proceeds to play video games in the video game room while Cole and Zane observed together from afar. Kai approaches them commenting that he's playing the game incorrectly, but Cole and Zane admit that Lord Garmadon is fascinating without his villainous intentions.

Meanwhile, in the Forest of Tranquility, the Falcon spots the Serpentine heading to the Fire Temple. Despite the footage being displayed on the screen in the bridge, Kai is too caught up in preparing himself for his "apparent" future battle to see it. Upon hearing Sensei Wu speaking to Nya, Kai follows their voices down the hall to overhear Wu speaking of the possibility of Nya becoming the Green Ninja. Lord Garmadon then confronts Kai about eavesdropping, which quickly results in the two declaring a fight. However, when they begin pushing each other, Nya rushes out to question them. Lord Garmadon informs her of Kai's snooping as well as calling the latter "Mr. Snoopypants". Shocked by this, Nya asks her brother if he is spying on her and Kai proceeded to lie that he is just keeping watch. Changing the subject, he asks her if she's the Green Ninja, to which she assures him otherwise, saying that she's content on being the Samurai. Jay then appears at the door, alerting them that the Falcon has spotted the Serpentine.

They all hurry back to the bridge to watch the monitor. Nya's analyses reveals that the volcano of the Fire Temple has awoken and become dangerously unstable since the last time they were there, noting that this place as a highly combustible environment. Zane questions the whereabouts of their weapons and Kai realizes that Lord Garmadon is missing as well. The Fire Ninja runs downstairs before Wu could stop him and finds Lord Garmadon with the four Golden Weapons in his possession. Immediately, they both spring into battle, with Kai closing the door as Nya comes by to investigate. The latter was immediately horrified when she saw her brother getting into a fight with Garmadon. When Jay tries to open the door, he realized that Kai had locked it. Nya then reveals to Wu and the other ninja the reasons behind Kai's actions and further revealed of his belief that he himself is the Green Ninja. Knowing that Kai would get hurt if he continues to fight, Cole breaks the door down using his True Potential, only to find Kai pinning Lord Garmadon to the ground as he declares himself the victor.

When Kai wonders on why he didn't unlocked his true potential, despite defeating Garmadon, Sensei Wu tells him that he can't defeat someone who allowed themselves to be defeated, and Garmadon reveals that he wasn't pilfering their weapons at all, but merely getting their weapons. When Kai protested that he was stealing them, Wu reveals that he had asked his brother to fetch the Golden Weapons and that he had no intention of using them himself. He further tells Kai off by saying that since he might harm someone then he shouldn't reach his true potential. Upon realizing that Garmadon was just going to get their weapons, the rest of the ninja are disgusted with Kai for his impetuousness, leaving him humiliated. As Wu and Nya help Garmadon up, the latter gives Kai a smug sneer, which caused the Fire Ninja to nearly lose his temper but he was able to calm down when Destiny's Bounty arrives at the Fire Temple.

Wu, Garmadon, and the ninja make their way to the temple grounds and Nya contacts the Ninja over Zane's falcon. She warns the Ninja that the real-time geothermal indicators are saying that with the eruption imminent, the entire environment of the Fire Temple is becoming increasingly fragile, which means that even the slightest rupture could make the whole place explode. To that end, Sensei Wu orders everybody to not use their golden weapons (especially Kai) and the gang ventures inside the inner core of the volcano where they watch the Serpentine dig for the Fangblade and Jay quickly points out Lloyd's location in a cage. Rattla uncovers the Fangpyre Fangblade, much to Pythor's pleasure. While Pythor gleefully gazes at the Fangblade, he notices the ninja in the reflection and orders the tribes to attack.

The ninja quickly fend them off, but Kai's efforts prove difficult at best because he can't fend off the Serpentine warriors with powers like everybody else. Eventually, when he is completely surrounded, he can't resist the urge to pull out his Sword of Fire and its mere presence inside the volcano initiates the final phase of its eruption. Nya announces that the golden weapon is compromising everybody safety over Zane's Falcon and the Serpentine make a break for it. Though as Pythor leaves the Temple, he commands Bytar and Chokun to drill holes in the walls to allow the now rising lava to quicken. Jay announces that they must leave as the Temple is going to blow any second, but Lord Garmadon runs after the Serpentine in an attempt to retrieve his son. Seeing that Lloyd is causing the trouble, Pythor orders the Serpentine to get rid of the caged boy by dropping him to the landing below. Lord Garmadon continues to fight the Serpentine to get the cage, finally reaching it and pulling up his son before his cage could fully melt in the lava.

Kai then rushes up the steps in order to obtain the Fangblade, flinging the Sword of Fire at the Fangblade to impale it in the wall. A furious Pythor attempts to pull it out, but Skales alerts him that they must leave at once, Pythor complying as the lava shoots up at them. Everyone except for Kai meets up at the exit and Lloyd calls out to his missing teammate as Kai makes his way to the Fangblade. However, the ground beneath Lloyd breaks loose and Lloyd falls down to the lava below. The group watches in horror as Lloyd stands on the sinking landmass.

Meanwhile, Kai finally pulls his sword out of the wall, but the Fangblade falls down below, landing just inches above the lava. Kai tries to grab it but chooses to save Lloyd instead when the latter cries out for help. He grabs Lloyd and tries to escape, but they become surrounded by lava geysers erupting all around them with the volcano finally ready to blow. Everyone else reaches the Destiny's Bounty and the volcano erupts, leaving the gang are distressed to see molten lava exploding out of the volcano, believing that Kai and Lloyd had perished. In the middle of their remorse, they suddenly see a glowing fire bubble rise out of the blast cone, which floats toward the Destiny's Bounty. When it gets closer, that fire bubble is revealed to be Kai carrying Lloyd inside, meaning that Kai has finally unlocked his true potential. Wu gives him a proud look before Kai passes out from exhaustion.

Later in the bridge, Lloyd reunites with his father, asking how he got four arms. Lord Garmadon genuinely thanks Kai for saving his son, and Zane asks the latter on how he unlocked his True Potential. Kai explains that his moment of truth arrived when he had to make a choice, because all he wanted was the fang blade to prove he was good enough to be the Green Ninja. When he prioritized Lloyd's safety over his personal glory, he realized his obsessive training and vigorous preparation to be the best ninja was not in preparation to become the Green Ninja, but rather to protect him.

Shocked at what this could mean, everyone looks to Lloyd and Nya places the Golden Weapons in front of him, which causes the weapons to become suspended in the air, crackling with green lightning just like Wu said they would when he explained how they would react in the presence of the chosen one. Sensei Wu comes to the conclusion that Lloyd is indeed the destined Green Ninja, elaborating that the four ninja have not only been chosen to protect the golden weapons, but also to protect the chosen one. Lord Garmadon's joy is shattered when he realizes the implications, and Wu sadly confirms that their family has only become more divided: as the Chosen One, Lloyd will have to battle his own father for the fate of Ninjago. As everyone is speechless about the heavy revelation and the events to come due to it, Jay feels the need to question what became of the Fangblade.

Back at the Fire Temple, as the Serpentine slither down the slopes of the volcano, Pythor spots the Fangblade in a lava flow. He carefully plucks it out of the magma using his Staff, offhandedly throwing it to Spitta and Lizaru. As the Venomaris flail around with the red-hot artifact, Pythor chuckles to himself because the Serpentine are now only one Fangblade away from reviving the Great Devourer. In the dark of night, a Venomari Soldier flees through the streets of Ninjago City to no avail, as the ninja corner him in an alley, demanding information on Pythor's whereabouts. The Soldier reveals that Pythor is on the trail of the fourth and final Fangblade; worse yet, the ninja are days behind him. The Venomari gloats that the Great Devourer will soon be revived, but his glee turns to panic when Zane points out that the Serpentine will be at risk along with the rest of Ninjago.

Back aboard Destiny's Bounty, the ninja worry about the Serpentine's progress in the race for the Fangblades. Lloyd suggests finding the Serpentine's inner sanctum to retrieve the other three Fangblades before Pythor can return with the fourth—however, Lord Garmadon reminds him that they have no leads on the location of the Serpentine's new base. However, Nya realizes that the Serpentine have been moving underground, and uses the ship's sonar to scan below the surface. Sure enough, the scan reveals that the Serpentine have dug a massive network of tunnels to connect their individual tombs, with the Constrictai Tomb being the most heavily-guarded. With a lead, at last, the ninja, Nya, and Master Wu all move out, with Lloyd and Lord Garmadon remaining aboard the Bounty.

Breaking into the underground fortress, the ninja engage the Serpentine forces, using their equipment and training to nullify the snakes' special abilities. Kai fights the Hypnobrai with his eyes closed to avoid their hypnosis, Jay's armor proves too tough for the bite of Fangpyre general Fangtom, Cole shimmies his way out of Constrictai general Skalidor's coils, and Zane uses Falcon Vision to get around the effects of the Venomari venom. Unfortunately, their attempt to seize the Fangblades is thwarted by a cage trap that springs up around them, just in time to be mocked by a returning Pythor.

On Destiny's Bounty, Lloyd and Garmadon get into an argument when Lloyd finds his father downloading data from the Bounty's computers. Garmadon claims that he can't help being evil as it's literally in his blood, but Lloyd retorts that Garmadon shouldn't have come back at all if he can't prevent himself from doing bad things. When Nya calls the ship, asking for reinforcements, Lloyd tells Garmadon to go back to the place where he came from before going on his first mission as the Green Ninja.

Back in the fortress, the ninja, Nya, and Wu are imprisoned in a cage made of Vengestone, high above the main chamber. Pythor reveals that he has found the final Fangblade, allowing the Serpentine to reawaken the Great Devourer. The Anacondrai orders everyone to return to the Lost City of Ouroboros immediately, but the others are reluctant; Chokun points out that they worked hard on the fortress, and Acidicus asks if they can celebrate first. At Skales' urging, Pythor relents, and the Serpentine proceed to have a massive Slither Pit tournament. Although Kai devises an escape plan—slipping out of the cage with Jay's hair oil and swinging to freedom on a chain—Pythor catches Kai moments after he makes the jump.

To prevent further interference, Pythor has the ninja bound to the bars of the cage, only for Lloyd to arrive in a dramatic but clumsy fashion. He challenges Pythor, but he is inexperienced and hopelessly outnumbered; the Serpentine all laugh at Lloyd's wild posturing. However, Lord Garmadon arrives with reinforcements: the Skeleton Army, declaring that he may not be able to help from being evil, but he can certainly choose to focus his wrath on the Serpentine to ensure that he is the only one to take over Ninjago.

Pythor is surprised by the intervention, reminding the Skulkin that Garmadon destroyed their old leader, but Kruncha retorts that "everyone hates snakes!" As the Skeletons battle the Serpentine, Lloyd frees the ninja from their cage—together, they steal the four Fangblades while Lord Garmadon forces Pythor into retreat. With the Fangblades in their hands, the ninja and Garmadon fall back to Destiny's Bounty while the skeletons continue their battle with the Serpentine.

Aboard the ship, Lord Garmadon prepares to leave, telling his son that there is nothing more he can do for him. He also tells Lloyd that he is proud of him, even if their destinies have forced them onto opposite sides of the inevitable final battle. With his father gone, Lloyd goes to meet his friends, who are celebrating their retrieval of the Fangblades; upon hearing of Garmadon's departure, all present offer a toast to Lloyd's father as well.

Sensei Wu declares that tomorrow, they will be able to destroy the Fangblades at Torchfire Mountain, but someone thinks otherwise—Pythor himself is outside the bridge, watching the celebration. Having slipped aboard the Destiny's Bounty during the battle, the Snake King is already plotting to recover the Fangblades and destroy the ninja once and for all. As the Great Devourer awakens and breaks free from her prison beneath the Lost City of Ouroboros, Sensei Wu tells the ninja that they "must do everything in their power to stop the Great Devourer." Nya leaves in her Samurai Mech, and a moment later the Great Devourer breaks free and procedes to swallow Pythor and Sensei Wu in a single gulp.

The ninja are devastated over the loss but are forced to retreat as the giant snake spots them. They all flee to the Destiny's Bounty with the Great Devourer hot on their tail. As Lloyd watches the Ninja returning from the cockpit, Nya orders him to fire up the engines. Lloyd informs her that there's no wind and the bounty is dangerously low on fuel. Nonetheless, they have to use it if they are to escape the deadly jaws of the megalodon-sized serpent. The Ninja arrive on the bounty as the Devourer begins to gain on them, and Nya takes off just before the Devourer can take a bite. When they gain some altitude, Kai thinks they're in the clear before the Devourer bursts out of the ground (having burrowed to blindside them). Nya is just barely able to steer clear of the Devourer's jaws and the chase is on. When Kai tells Nya the monster is gaining on them, Nya sets a course for Crashcourse Canyon. Zane predicts that the odds of making that distance on reserve fuel is less than 8% and Nya simply orders him to never tell her the odds at a time like this. Cole warns of the Devourer closing in for another attack from the starboard side and the Bounty is able to narrowly dodge her. However, Lloyd announces that the bounty is losing speed and will collapse dead to the ground pretty soon. In response, Nya orders everyone to throw all of their belongings overboard to lose weight and regain speed. Things only become more complicated when the Devourer bites off and eats the deport ballast. The Ninja proceed to lighten the load. However, the Great Devourer only eats all the items thrown away. Just when it appears the Bounty is regaining speed, Jay notices the Devourer somehow looks bigger than she did before. Suddenly, Jay is proven right when she spontaneously doubles in size right where she stands and that's when Cole realizes how the Great Devourer gets her name: "The more it consumes, the bigger it gets". Cole orders everybody to cease and desist with throwing anything else overboard before Kai throws away Wu's prized teapot.

Despite the loss of the ballast, the Destiny's Bounty is able to just barely reach Crashcourse Canyon, weaving away from the Great Devourer. Just as the ninja think they've lost the snake, she strikes the flying craft with her tail, forcing them to abandon ship in a devastating tailspin. The six of them are able to retreat to safety in their vehicles and the ninja watch in horror from a hollowed-out boulder as the Great Devourer bites their home in half, quickly leaving the scene in a burrow afterward. When she's gone, the ninja take a split-second to catch their breath after such a nerve-racking ordeal. However, Zane says that there's no time to lose and they must go warn others of the Devourer on the attack before she gets any bigger. Though, Jay has already given up any hope of defeating that giant monster serpent. So, he proposes the idea of gathering up as many survivors as they can and bunker down in one of the Serpentine Tombs to stay safe whilst the Devourer ravages the surface. However, Kai is unwilling to give up so easily after everything they've been through and gives the team words of encouragement obtained from the late Sensei Wu. The gang tries putting their heads together to come up with a plan, but a pessimistic Jay reminds everyone they have nothing to fight back with; the last Sacred Flute was taken by Pythor, their dragons have long departed to the spirit coves to complete their metamorphosis, and Jay doubts their golden weapons will have any effect. Cole agrees, saying that they'd need a weapon of monumental proportions to make a mark on such a massive beast. That's when Kai is struck with an ingenious idea despite Jay doubts, Kai proceeds to put his own plan into motion; a plan that will guarantee the destruction of that bloodthirsty monster once and for all.

Meanwhile, the Serpentine retreat to the Fangpyre Tomb as Fangtom and Skales argue over the latter's role in Pythor's insane plot. They have all come to realize that awakening the Great Devourer was a kamikaze plan from the beginning, as it spells the end of all life in Ninjago if she cannot be stopped. As they leave, they spot the Great Devourer close by and quickly rush inside.

The ninja arrive at Ed & Edna's Scrap N Junk, and Jay comes to the conclusion that his parents left. Kai whips out blueprints for his idea: the Ultra Sonic Raider. Zane also reveals that he has a recording of the Sacred Flute stored in his databanks. Kai explains the plan is to use all the parts from the scrapyard to build it with their biggest Tornado of Creation yet when the Postman appears with mail for Ed and Edna. The ninja tell him that he should be leaving because their plan will be too collateral for anybody to be around. The Postman doesn't understand the situation and thinks they're referring to the Take Back Ninjago rally—apparently, everyone is gathering in Ninjago City for an anti-Serpentine rally. While the Postman is talking, the Great Devourer creeps up behind him, prompting him to hide inside a garbage can.

Ready to fight, the ninja use the Tornado of Creation to draw in spare parts from the Junkyard and build the Ultra Sonic Raider in mere seconds. With the vehicle primed and ready, Kai tells Zane to play the recording of the Sacred Flute emitted through twin sonic cannons, but the Great Devourer dodges the attack. Cole criticizes Zane for his lousy aim and Zane responds with the reminder that the 4 of them literally just built the humongous vehicle from scratch. After several failed attacks from both sides, the ninja use a grappling hook to keep the snake still long enough to use the sonic cannons playing the melody of the flute against her. As the Devourer writhes in pain, Kai notices a weak point on her head in the form of a tiny glowing spot. He tries to elaborate to his friends, but his voice is drowned out by the sonic cannon. Before he can make himself clear, the Great Devourer burrows her tail underground and strikes the Ultra Sonic Raider from behind, destroying the sonic flute and Zane’s command chamber with him in it.

The snake retreats from the Junkyard and Zane emerges from the attacked portion of the Ultra Sonic Raider, mostly unscathed save for the exposure of the robotic parts on the left side of his face. Jay thinks the operation was a complete failure, but Kai quickly points out they now know the Great Devourer has a weak spot on the crown of her head. As Jay retorts that there's such knowledge is no use, the ninja realize that the situation has worsened further; the Great Devourer has set her sights on Ninjago City. Kai declares that when the Devourer reaches the resulting size if she is allowed to devour the biggest city in all of Ninjago and everybody in it, all hope will be lost as there will be no defeating her.

Just as everybody is enjoying the rally, the Ninjago Metro workers notice something entering the city on track 9, even though there are no trains scheduled for that track. That’s when the Great Devourer makes herself known. She enters the city through the Ninjago Metro system and breaks out onto the streets through the surface entrance. She winds up at the middle of the rally and scares off everyone. Ed and Edna try to escape in their Jalopy, but the engine doesn't start—luckily, Jay arrives to blast the Devourer before she can eat them. The other ninja join the battle and attempt to deter the Devourer with every attack at their disposal, but their efforts only seem to make her angry. As the beast rampages, camera crews are capturing every moment of the battle on live coverage.

Meanwhile, Lord Garmadon enters Mystake's Tea Shop to request some Traveler's Tea; Mystake comments that only fools take that blend, but redacts her statement when she sees who she's talking to. While Lord Garmadon waits for her to come back with the tea, he sees the ninja losing their fight against the Great Devourer on television.

Nya and Lloyd attempt to stop the Great Devourer by wedging a street light in her mouth using the Samurai Mech, only to get stuck when the Devour's struggling causes a malfunction in the suit. Before they can be consumed, a giant white dragon swoops in to the rescue. This beast is revealed to be none other than the ninjas' elemental dragons, which have now returned merged into the four-headed Ultra Dragon upon having completed their metamorphic transition into adulthood. Zane declares that they too have reached their true potential and cheer it on as it saves Nya and Lloyd, attacking the snake with its four combined elements. The assault seemingly forces the Great Devourer to retreat, but as the Ultra Dragon glides to its allies, the serpent's tail shoots out of the ground and knocks the dragon out of the air, completely subduing it.

As the ninja assess the damage done to the Ultra Dragon, Lord Garmadon appears behind them while the Devourer continues her rampage. He demands for the Golden Weapons—their combined power is the only thing that will destroy the Great Devourer, but only he can wield all four at once. The ninja are hesitant—with Jay pointing out that their mission is to protect the Golden Weapons from Lord Garmadon—but Zane admits that their foe's suggestion is more feasible than any other scenario he can calculate. Deciding that they have no other choice, the ninja hand over their weapons, with Kai telling Lord Garmadon about the Devourer's weak spot. Although clearly pleased to have the Golden Weapons, at last, Lord Garmadon stays focused on the current crisis, telling the ninja that they must immobilize the Great Devourer long enough for him to get a clear shot at her weak spot. As the villain runs off, Jay despairs at their task, but the ninja come up with a plan.

As the Devourer already starts becoming absolutely humongous just as they feared, the Ninja keep the beast on the run by parkouring through the city, keeping her on their tail. Kai begins their plan by confronting the Great Devourer alone, luring her through the street to where Cole is waiting. Cole then lures her to a dead-end alley where she goes to a rooftop where Jay stands, and Jay leads her through a construction site to meet up with Zane. Jay and Zane escape using an ice slide that Zane created with the Devourer in hot pursuit. Right before they are devoured, Kai and Cole swoop in on the Ultra Dragon to pick them up. From the bird's eye view of the flying dragon, the ninja see that their plan has worked; with the Devourer's oversized body tangled among the buildings of Ninjago City, she is completely stuck with her tail wedged inside her mouth. They take refuge on a nearby building and wonder where Lord Garmadon is since the Devourer won't stay stuck for long.

The skies darken and clouds swirl as Lloyd spots Lord Garmadon, standing atop a skyscraper with all four Golden Weapons in hand. With the Great Devourer right beneath him, he condemns her as the one who forced him down the path of evil, and charges up the power of the weapons. In an act of vengeance, Lord Garmadon jumps and dives down from the skyscraper, impaling the Devourer's weak spot with the Golden Weapons right on impact. Roaring in agony, the Great Devourer surges with energy and explodes into a tsunami of venom that washes over the entire city. The all-consuming Great Devourer has finally been defeated and the citizens of Ninjago City cheer in their victory.

From the Serpentine tomb, Skalidor and Fangtom both note that they hear cheering, which can only mean the Devourer was destroyed, to which Skales mentions that they will need a new leader now that Pythor is out of the picture.

The ninja rejoice with their families and their new dragon when Lloyd notices that Lord Garmadon is nowhere to be found, which means the Golden Weapons are gone too. Kai deduces that they'll probably be seeing him again soon, but Lloyd tells him that's what he's afraid of. However, their spirits are lifted when Cole sees Sensei Wu alive amongst the venom, and the ninja excitedly rush over to greet him and celebrate their victory. Sensei Wu greets the ninja by finding his teapot and washing out the bad taste the Devourer left in his mouth with the hot tea it contains. As happy as Lloyd is to have Sensei Wu back, he wastes no time informing him that Lord Garmadon has absconded with the Golden Weapons. However, Sensei Wu simply tells him that the spirit of the weapons still lives on in Lloyd and his four students have become the masters who will train Ninjago's greatest hero. His mood quickly turns melancholy as he remembers that he will have to fight his own father as the Green Ninja one day. While today, they can enjoy their victory, tomorrow, Lloyd will begin his training for that day. The others nonetheless promise to train him in everything they know and they will help him reach his full potential before that day comes. With victory declared and their future bright, the Ninja end the episode and the season with a group victory leap, shouting “GO, NINJA, GO!” The Falcon flies through the air, watching the ninja help rebuild Ninjago City when Sensei Wu and Nya ride up telling them they found a new home. Meanwhile, Skales is attempting to convince the Serpentine to let him be their leader, when Lord Garmadon appears and tells them they should follow him. After reconstructing the destroyed Destiny's Bounty, creating the Black Bounty, and threatening the Serpentine should they not follow him, they agree. However, instead of flying the Bounty to Ninjago City, Garmadon flies in the opposite direction to the Golden Peaks, to unlock the full potential of the Four Golden Weapons. He tells the Serpentine that he doesn't plan to destroy Lloyd, but rather, the ninja and Wu so that Lloyd won't reach his True Potential.

Meanwhile, the ninja are house-hunting. The only place they can afford turns out to be a one-bedroom, one-half-bath apartment without lighting. Jay and Kai argue that they need a better place to train Lloyd, and the ninja agree to buy an expensive hero suite that's out of their price range. To make enough money for rent, they each search for jobs. Jay takes up a job delivering pizza, Cole becomes a security guard at the bank, Zane becomes a chef at a restaurant, and Kai works as a party entertainer. However, the jobs end up being so difficult that when they return home, they're too tired to train Lloyd and they are nowhere close to making rent.

The Serpentine generals are not about to let Garmadon lead the Serpentine, and they brainstorm on a diabolical plan to convince the Serpentine to follow them. While delivering a pizza to them, Jay overhears their plan but is captured by Acidicus before he can alert the other ninja.

The first step of the plan is for the generals, excluding Skales, to rob the bank. Since Cole was too busy napping, he is unable to stop the generals before they get away, but he overhears them saying they're heading for the Ninjago Metro. Kai and Zane are instantly alerted but are fired when they leave or are distracted from their jobs. After Cole is fired for sleeping on the job, the three ninja head off to stop the Serpentine. They head to the subway and manage to infiltrate the Serpentine's train and fight the Serpentine, but they have difficulties without their weapons. The Serpentine reveal their plan wasn't to steal the money, it was to distract the ninja so Skales could kidnap Lloyd and use him as leverage against Garmadon so that he can be the new Serpentine leader.

In the apartment, Lloyd is alone playing a video game when Skales breaks in. Although Lloyd attempts to get out, the door is locked and he can't unlock it. Just before Skales could get Lloyd, they both hear Sensei Wu and Nya on the opposite side of the door. Lloyd screams for their help from the other side of the door.

Back on the subway, Cole reminds everyone that they have to save Lloyd and Zane shows the others the makeshift weapons they can use to fight the generals off. The ninja manage to corner them, but before they can defeat them, Cole notices the train is heading straight for Jay. They find that the train is automatically controlled and pull the break before it can hit Jay, which gives the Serpentine time to get away.

The ninja head back to the apartment to find it empty. They instantly regret taking the jobs and agree that losing Lloyd was their greatest loss. However, Sensei Wu and Nya appear in the doorway with Lloyd. The ninja realize they didn't need all of the fancy stuff and only need each other. Upon realizing this, they move to the crowded apartment they were first shown so they won't be distracted and can train Lloyd. When Kai asks what happened to Skales, Sensei Wu reveals that he's been thrown in jail. In prison, Skales swears to return.

On the Golden Peaks, Garmadon successfully manages to merge the Four Golden Weapons into the Mega Weapon. Although it appears to be painful, he tells the Serpentine he's never felt more powerful, stating he will destroy the ninja once and for all. Garmadon releases an evil laugh that is show to ring throughout Ninjago. Meditating, Sensei Wu says that he fears "there is a great disturbance in the force.“ The episode begins with Lloyd honing his elemental powers, by using his Lightning to power a lightbulb. Despite Jay's encouragement, Lloyd loses control of his powers and destroys the lightbulb, much to his anger. Sensei Wu reassures Lloyd that he will become more skilled with time—he spent his childhood hoping to follow in his father's evil footsteps, and it will take time for him to embrace the light. Nya arrives and invites Jay to come to the autobody shop where's she's gotten a part-time job and fixes the Ultra Sonic Raider in her off-time. She also brings a letter for Lloyd from the Darkley's School for Bad Boys. It says that they have now been inspired by Lloyd's change and have become the "Darkley's School for Great Children". They invite Lloyd to receive an honorary award of excellence.

On the Black Bounty, Lord Garmadon asks his crew of Serpentine what their next tactic should be to destroy the ninja. After having heard suggestions to recreate the Great Devourer, create more pirates, and create a giant ham sandwich, Garmadon becomes enraged and contemplates a plan. After seeing his reflection in the Mega Weapon, he orders the Serpentine to gather the ninja's clothes and creates the evil ninja.

Meanwhile, the ninja head to Darkley's School For Great Children and are immediately greeted by Brad Tudabone, one of Lloyd's classmates who had previously put fire ants in his bed. The ninja are immediately surprised to see none of the students or teachers in the school, although Brad insists it's Ninja Day and they're all staying hidden in honor of the ninja.

Brad leaves the five in a room to speak to Principal Noble, but it turns out to be another student named Gene. He reveals that they haven't been inspired by Lloyd, but have become worse before dropping sandbags on them. The ninja awaken in a locked room filled with the new teachers, who reveal that once they tried to change the school, the boys trapped them. Furthermore, the award was only a trick to lure Lloyd in so they can make him their leader.

Back in Ninjago City, the clones are searching for the ninja. They arrive at the dojo, but Sensei Wu tricks them into revealing that they aren't truly the ninja. However, he's immobilized by the clones. Before they can begin interrogating him, they hear a call from Nya to Jay asking if he's still coming to the autobody shop.

At Darkley's, the ninja find difficulties getting out of the room. Jay reminds them that he's supposed to meet Nya at the autobody shop, and since he's so punctual, she'll know something's up. This fails, though, when the clone of Jay arrives and tricks Nya into revealing where the ninja are. After the fake Jay kisses Nya to steal the key to the Ultra Sonic Raider, the clones then make off in the vehicle and head to Darkley's.

Zane realizes that since the school was originally made for evil, there must be hidden passages. They manage to find a way out, although they set off two boobytraps in the process and find the path they take overrun by spiders. Meanwhile, Lloyd tries to convince the other students he's evil, though they don't fall for it. The evil ninja soon arrive, and the students are shocked, mistaking them for the real ninja. Although they try to fight them off, they're quickly defeated. They then capture Brad and demand to know where the real ninja are.

Lloyd manages to use his inability to control lightning to free himself, but the students arrive soon after telling Lloyd that the ninja have turned evil. The clone ninja hurry to the room the ninja were trapped in, and are furious to see it empty. However, the real ninja arrive and they begin fighting their counterparts.

When Lloyd tells the students they need to help the real ninja, they tie him up again. Gene concludes that if either the real or fake ninja could get a hit on their double, one would disappear and tells them that they should help the evil ninja defeat the real ninja. Lloyd reveals that he's been lying and that he is good, but that Brad is too. He recalls that on his first day, Lloyd didn't know how things worked around Darkley's, and although Brad put fire ants in his bed it was only to show Lloyd how things worked at Darkley's. Lloyd tells the students that each of them have a secret good side to them that stays quiet out of fear of being alone. Realizing this is true, the boys join Lloyd.

To help the ninja, the students sew ninja suits and head out, planning to confuse the Bizzaro ninja during the battle. The plan works, allowing the ninja to land blows on their counterparts, causing them to dissipate, during which the fake Jay tells the real Jay that getting rid of them won't be that easy, but an enraged Jay manages to defeat his counterpart once it's revealed that he kissed Nya. The teachers enter as soon as the clones are defeated, and tell the boys that although they should be punished, they're going to hold a ceremony in celebration of them becoming good. The ninja head back home in the Ultra Sonic Raider and on the Ultra Dragon after the ceremony. However, Garmadon appears on the screen of the Raider. He tells the ninja he will find new ways to destroy them but is cut off by static.

Zane assumes that the Raider is still damaged, but Lloyd reveals that he's the one doing it. He then uses his power to change the screen to a Tetris-like video game without breaking anything. The episode begins with Lloyd's training in Dareth's dojo. In preparation to bear the fate of Ninjago on his shoulders, he is doing a one-handed handstand while balancing the ninja and Sensei Wu on his feet. This goes surprisingly well, but Lloyd drops them when a wrecking ball crashes through the dojo's wall.

As Dareth rushes in to assess the damage, the operator of the wrecking ball explains; Dareth has fallen behind on his dojo payments, though Dareth says they would have started the next day if he didn't have the money. Unless he can pay fifty thousand dollars, a company named Darnagom Enterprises plans to buy the entire block and put in a frisbee golf course. Zane realizes that "Darnagom" is an anagram of "Garmadon"—their perennial foe, Lord Garmadon, is trying to destroy the dojo so Lloyd will have nowhere to train. Nya tells the ninja that the Ninjaball Run, the biggest and most dangerous road race in Ninjago, is the next day and the grand prize is one hundred thousand dollars. The four ninja decide to enter with the Ultra Sonic Raider and Lloyd enters with the Ultra Dragon.

The next day, the race is about to begin. Nya shows up to tell the ninja about a special addition she added to the Raider in case they need it, activated by a lever, but because of the uproar, they are unable to hear what it does, and Nya has to leave before she can explain it again. Soon after, the other racers make their way to the starting line, including the Royal Blacksmiths, Ed and Edna, Captain Soto and his pirates, Kruncha and Nuckal, Gene and Brad, and the Mailman. The race begins, and the contestants race off—except for the ninja, whose Ultra Sonic Raider loses a track (due to Gene and Brad tampering with it before the race).

Meanwhile, the Serpentine Generals succeed in freeing Skales from jail and they escape on a Charter Bus. However, the police pursue the four and in an attempt to escape, they accidentally join the race, much to the confusion of Skales. Back at the starting line, the ninja succeed in fixing the Raider and join the race again.

On the Black Bounty, Lord Garmadon is shocked to see the ninja participating in the race and decides to cut in to ensure they won't win. The race has now changed terrain to the desert where the Pirates crash into the rocks and are put out of the race, due to No-Eyed Pete's driving. Just as the ninja start to catch up to the other racers, Lord Garmadon appears and begins to shoot at the ninja, but Lloyd accidentally crashes the Ultra Dragon into the ship, causing the shot to miss them. After the talk it over, Lloyd and the ninja decide to work together to win.

At the Birchwood Forest just as Lloyd points out a shortcut for the ninja to take, the Ultra Dragon is brought down by Kruncha and Nuckal, but they crash soon after. The action then cuts to the stands, where the announcers ask Dareth the ninja's purpose in participating. After Dareth tells them how they're trying to save the dojo, the crowd energetically cheers for the ninja.

Back on the race track at the Glacier Barrens, the ninja notice their gas is running out. Ed and Edna, after hearing about the dojo, offer to give them their gas, but if the ninja stop they'll be put in last place. The only option is for them to connect a pipe to both gas tanks and transfer the gas while they're racing. Lord Garmadon interferes and sends the Serpentine to stop them. Although this fails, Ed and Edna's car is wrecked in the progress. Jay takes a piece from their car and attaches it to the front of the Raider to ensure that at least a piece of their car would make it to the finish line.

The race is in its final stretch, and Lord Garmadon and the ninja are in the lead. To ensure he wins, Lord Garmadon wishes for a divide that the ninja will not be able to cross. Although hope seems lost, Kai uses the lever that Nya installed which causes the Raider to fold out hidden wings and cross the divide. Both Lord Garmadon and the ninja fight for the lead, but the ninja win by the piece from Ed and Edna's car crossing the finish line first.

Lord Garmadon argues how it isn't fair since that wasn't part of their vehicle, to begin with. He then realizes that while he stepped off the Black Bounty, Lloyd has gotten on and regained it for the ninja. The police arrive soon after and inform Lord Garmadon he is under arrest, but Skales pulls in and Lord Garmadon escapes with the Serpentine. As Nya points out that it's not the last time they'll see him, Dareth celebrates the Dojo being saved by cannon-balling into the money-filled trophy. The episode begins with the Destiny's Bounty flying over the Jamanakai Village, with Lloyd lamenting that he must train and not play with others or enjoy his youth. Nya then tells the ninja that Lord Garmadon has been spotted at the Museum. As the ninja leave, Lloyd complains to Nya about being too old for comics, but too young to fight, before she offers him to fight her.

Once there, Lord Garmadon tells the Serpentine he is going to revive the extinct Grundle in another attempt to destroy the ninja. As he is using the Mega Weapon, the ninja watch, then burst in and interrupt the process.

Garmadon leaves in a hurry, while the Serpentine Generals steal a golden sarcophagus for compensation. The ninja chase after them but fall behind. The Generals can't fit the sarcophagus through a manhole with them, so they left it behind and escape. The ninja then realize they have been turned into kids. When the police arrive on the scene, they accuse the ninja of the theft and place them under arrest. They take them back to the museum the following morning to apologize for their actions. The museum director accepts their apologies, but questions where the Grundle fossil has disappeared to. The ninja realize the Grundle must have been revived after all, and with the cops not believing them, the ninja escape and disguise themselves and run off with some school kids that are on a field trip. The Grundle appears on top of the museum, scaring a crowd of people in the surrounding area.

Sensei Wu and Nya, worried that the ninja haven't returned yet, leave Lloyd behind to go search for them. As Lloyd is playing a video game, he receives a call from Jay telling him to meet them at a pizza parlor and to bring their weapons, since they can't ride the bus without an adult. Lloyd is confused but quickly arrives. When they meet up, Kai informs Lloyd of the situation and the group wonders what they should do about the Grundle. Lloyd, knowing exactly who would be the most knowledgeable on the creature, brings them to a comic book store and introduces them to the sales clerk, Rufus McCallister. Rufus informs him that Illuma-Swords would work well, as the Grundle is nocturnal, but the shop only gives them out as a prize for winning a comic book trivia competition. Lloyd leaves a message for Master Wu and Nya back at the Destiny's Bounty, quickly telling them of what happened and their current location. Master Wu and Nya then go to Mystake's Tea Shop for Tomorrow's Tea to turn the ninja back into their older selves and the Grundle back into bones.

Meanwhile, Lloyd loses the competition (due to the final question being from a last-issue comic that had just sold out) and the Grundle shows up. The ninja grab the Illuma-Swords to defend against the Grundle, but because they were meant as props they break easily. Lloyd attempts to take on the monster with his powers but is quickly knocked aside. Just as the Grundle is about to consume the ninja, Master Wu and Nya arrive with Tomorrow's Tea, tossing it to them and telling them to use it to age the creature back into bones, as well as themselves back into their normal states. The ninja are hesitant once they realize it would mean Lloyd growing older as well and missing out on his childhood. Lloyd, accepting the consequences, uses the tea to defeat the Grundle. The ninja are returned to normal, but now Lloyd has become their age as well. The episode ends with Rufus handing Lloyd his last-issue comic, which he says he has earned. Lloyd declines, saying he already knows how it ends. Aboard Destiny's Bounty, the ninja train Lloyd with a variety of weapons and skills. Nya comments that Lloyd has become a fast learner now that he's aged, but Sensei Wu tells his pupils to challenge Lloyd again, this time at full strength.

Just then, the Falcon arrives and shows the Serpentine back in the City of Ouroboros, apparently preparing for a final battle. The ninja head to the city and arrive at night. While Fang-Suei works on the Fangpyre truck, Sensei Wu and the ninja confront Lord Garmadon, only for Lloyd to arrive and freeze the tip of the Mega Weapon. Garmadon is surprised to see his son as a young man, and Lloyd explains that things have changed since they last met.

While Fang-Suei, Chokun, and Mezmo battle the ninja with their power tools, Lord Garmadon escapes and hides in a nearby building. As he tries to break the ice off of the Mega Weapon, he laments the ninja's continued interference, wishing that they never existed. This statement inspires him to create a time portal and step through it. The ninja find the portal as sand begins to rise, which Zane identifies as the City of Ouroboros returning to the desert as if it had never been found in the first place. The heroes realize that Garmadon is manipulating the past, preventing the ninja from ever forming and training Lloyd—sure enough, the Green Ninja comments that he can no longer feel his hands. The ninja decide that they have to follow Garmadon into the past, with Sensei Wu warning them that "if he changes anything, he changes everything."

The four ninja jump into the portal and land in a muddy rice field, not far from Four Weapons in Ignacia. They realize that they have returned just as Master Wu's past self was attempting to recruit Kai for his academy to become a ninja and when Past Garmadon ordered the Skulkin to find the Map of the Golden Weapons and to capture Nya (as seen in "Way of the Ninja"). At first, Kai wants to warn Past Kai and Nya about the Skulkin, but Zane explains that any changes to the past will affect the future dramatically. After Past Master Wu leaves the shop, the four ninja ambush him and explain their situation—realizing too late that they have inadvertently changed the past in the process. Despite this, Kai persists in asking Past Master Wu for his aid. Although confused by the events, Master Wu agrees to help.

Moments later, the Skulkin burst onto the scene to capture Nya and to find the map, with Garmadon disguised as a Skulkin manning the Skull Truck. While the present ninja watch Past Kai and Nya fight the Skulkin, Zane suggest they should fight a few skeletons as long as Kai's past self and Nya doesn't see them much to Jay's delight as he misses beaten the Skulkin up. A group of Skulkin sneak behind them, but Jay defeats them with ease with his Spinjitzu. After Kai warns Past Master Wu about the impending events and his role in them, all goes as before until Samukai commands Kruncha to kidnap Nya. Instead, Garmadon forces his way past Kruncha and intentionally fires the truck's bone hand to miss Nya. The Skulkin retreat, but not before a confused Nuckal sees the two Kais, although he ignores it. In the present, a wave of dark clouds looms over Ninjago City, and a picture of Lloyd from a portrait disappears, indicating that he is no longer with the ninja in the present.

Back in the past, Kai realizes that he misinterpreted Garmadon's plan—by preventing the Skulkin from kidnapping Nya, he has removed Past Kai's reasons for becoming a ninja. As Zane explains to Jay and Cole if Kai never becomes a ninja, all of their actions in the future will be undone: the four of them will never become a team, Lloyd will never be trained to become the Green Ninja, and Nya will never fall for Jay. At this last fact, Jay desperately tells Past Master Wu to recruit Past Kai no matter what—although Past Kai is reluctant, Nya encourages him to go, thinking that it could be a fun experience.

The Present ninja soon find themselves located at the past Monastery of Spinjitzu, watching Past Nya and Past Kai training. However, Past Kai is barely interested in training—the Present ninja realize that Kai's only motivation to train well was Nya's kidnapping at the hands of the Skulkin. Consequently, Zane resolves that they must kidnap Nya and hand her over to the Skeleton Army to motivate Past Kai and set events back on track. That night, Zane, Cole, and Jay disguise themselves as Skulkin and kidnap Nya—meanwhile, Kai acts as his past self's reflection in the bathroom mirror, then tells Past Kai he should start listening to Sensei Wu. Meanwhile, as Jay, Cole, and Zane take Nya in a sack, the other three Past ninja, wearing their black suits, spot the three Present ninja. As the three ninja fight their past selves, Past Kai hears Nya's cry for help, forcing Kai to knock him unconscious. With their ally in the outdoors battle, the Present ninja get away with Nya, and in the present, Lloyd's portrait is restored to its original state.

In the Forest of Tranquility, the four ninja find the Skulkin camp and drop off Nya in front of Kruncha. However, Lord Garmadon has realized that his foes are interfering with his plans, prompting him to appear before his past self in the Underworld. Although Past Garmadon is highly confused by the appearance of his future self (especially the fact that he has four arms), Garmadon quickly explains the circumstances and formulates a new plan with his past self. In the present, the dark cloud reappears over Ninjago City, larger than ever, and Lloyd's portrait disappears again.

Back at the forest, the Present ninja and Past Sensei Wu are watching the Past ninja sleeping around a campfire. Jay wonders why they haven't returned to the present, and Cole reminds him that they still have to make sure that the rest of the events play out as before. As Kai explains the significance of these events to Past Sensei Wu, Past Kai is lured to the Fire Temple by Nya—which Kai explains is a trick by Lord Garmadon in order to eventually unleash a great evil.

The Present ninja and Past Sensei Wu follow Past Kai to the temple, where they watch Past Kai claim the Sword of Fire and use his Spinjitzu to save Nya. However, Kai realizes something is wrong when Past Garmadon responds to Past Kai's taunts differently than he remembered. Suddenly, Past Kai is attacked—not by his own shadows, but by the present version of Lord Garmadon.

Realizing that his past self doesn't stand a chance against the four-armed Garmadon and his Mega Weapon, Kai grabs the Sword of Fire when Present Garmadon knocks it from Past Kai's hands and leaps into the fray himself. Cole and Zane join in, but even three Present ninja are unable to defeat Present Garmadon. As the dark warlord celebrates with his past self, Zane comes up with an idea: by destroying the Mega Weapon, they might be able to undo all of the changes to the present. Although Kai agrees (despite Zane admitting that it's only theoretical), Cole points out that the only way to destroy the Mega Weapon is to use something of equal power—and no weapon can equal the power of the Mega Weapon.

At this, Jay disagrees; he brought the other Golden Weapons for the Present ninja to use. With their ultimate weapons in hand, the Present ninja combine their elemental powers and blast the Mega Weapon, while Past Master Wu uses his own powers to pull it out of Present Garmadon's hands. As everyone looks on, the Golden Weapons are pulled from the ninja's hands and combine with the Mega Weapon, hurling it into space before it explodes brilliantly. Nya vanishes into thin air, Past Kai demands to know what's going on, the entire volcano begins to crumble as it is engulfed in light. . . .

. . . and the ninja find themselves back in the training room of the Destiny's Bounty. For a moment, they fear that Lloyd is no more, but Lloyd quickly rushes into the room, apologizing for being late. The ninja embraces their comrade, thankful that the timestream is back in order—however, Lloyd is confused by their talk of Lord Garmadon's Mega Weapon; apparently, when the ninja destroyed the Mega Weapon in the past, Lloyd's knowledge of the Mega Weapon was erased, except for those present during the Mega Weapon's destruction.

As the perplexed Lloyd uses a sword to carve a slice of watermelon into a dragon sculpture, Kai tells him not to worry about it—some things are best left in the past, so they can focus on preparing for the future. Meanwhile, Master Wu is looking at what is presumably the remains of the Golden Weapons, a distant, bright star in the sky. In the Lost City of Ouroboros, Lasha and Lizaru are fighting in the Slither Pit arena. The fight is interrupted when the Rattlercopter lands in the arena, prompting Chokun to set up a red carpet with a seat and an umbrella for Lord Garmadon. The four-armed villain informs the Serpentine Generals that he has an ingenious plan, saying that Captain Soto's journal mentions a fabled island known as the Island of Darkness. Skales is skeptical, but the Generals leave with Lord Garmadon in the Rattlercopter.

Lloyd destroying the alarm clock Lloyd destroying the alarm clock At the Destiny's Bounty, the ninja are awakened by their alarm clock, with Lloyd tiredly using his powers to destroy it. Sensei Wu comes into their room telling them that the Ultra Dragon made a mess outside, and the ninja leave Lloyd to clean up the mess by himself. Lloyd argues, saying that they can't just push chores on him anymore. The ninja agree, and they play a round of "rock, paper, clamp" and Lloyd loses, so he has to clean it up anyway. The ninja watch, saying that having a dragon for a pet takes a lot of responsibility. They ask Lloyd if his mom let him have a pet, to which Lloyd replies saying that he does not remember his mom because she abandoned him when he was young. Nya then arrives, telling the ninja that there is an emergency at the Ninjago Museum of History.

When the ninja arrive, the Museum Curator tells them that the Great Devourer's venom worked its way into the sewer system and leaked into the Museum, bringing the Stone Warrior merchandise to life. As they all fight the aggressive Stone Warrior figurines, they make the merchandise room a mess in the process. However, one Stone Warrior toy slips out and Sensei Wu chases it down the hallway, though while smashing it he runs into Lloyd's mother, Misako. When Lloyd exits the merchandise room, Sensei Wu introduces her to the ninja. Upon meeting, Misako tells her son that she had her reasons for leaving, but Lloyd refuses to listen and leaves for another room to be alone.

While Lord Garmadon and the Serpentine Generals ride in the Rattlercopter, Lord Garmadon complains about being unable to find the island, and he orders Snike to turn the Rattlercopter around. Skales lies to Lord Garmadon by saying he has spotted the island, but once Lord Garmadon looks, Skales shoves him into the sea below. The Generals then declare Skales the new Snake King.

Back in the Museum, Misako finds Lloyd sitting at the edge of the bottomless sinkhole exhibit, to which she states that it is where she unearthed the Giant Stone Warrior. Misako explains that she abandoned him to learn everything about the Green Ninja prophecy, knowing that Lloyd would be the Green Ninja, and wanting to stop him and his father from fighting. She begins telling a story of the First Spinjitzu Master, and how he created Ninjago with the Four Golden Weapons. Misako explains that for there to be light, there must be a shadow, and in shadow, there is darkness. The darkest of shadow existed long ago, an evil spirit called the Overlord. The balance was at stake, and neither could conquer the other, so The Overlord created indestructible warriors called the Stone Army. Knowing that he would be defeated, the First Spinjitzu Master divided Ninjago in two, and since then, there had been no signs of The Overlord or his Stone Army, until Misako's recent discovery. As long as the balance remains even, The Overlord will stay trapped, and Lloyd is the only one who can stop it before Ninjago falls prey to darkness.

Then, while the Museum Director showcases the new Stone Warrior Statue exhibit, the Great Devourer's venom drips from the ceiling and onto the statue, bringing it to life. As Misako tells them that there is hope to prevent Lord Garmadon and Lloyd's fight, the Stone Warrior rampages through the Museum and confronts the ninja. They try to fight it off to no avail, and they are forced to flee the room and run through the Museum as they try devising a plan to defeat it. They stop inside a large room and close the doors, and as the Stone Warrior begins to break it down, Lloyd suddenly comes up with a plan and tells the ninja to confuse it. Lloyd leaves the room as the Stone Warrior breaks in.

Lord Garmadon washes up on the beach of the Island of Darkness, and The Overlord discovers him. The Overlord begins talking with Lord Garmadon, and Lord Garmadon demands that he give him the power to destroy the ninja and to make Ninjago into his image, but The Overlord says he needs to follow him first. The Dark Island emerges. At the Museum, Misako decides to help Lloyd by leading the Stone Warrior to Lloyd's location. After she meets up with him, Lloyd manages to trick the Stone Warrior into stepping over the fake floor paneling, revealing the giant sinkhole where it was unearthed. Once the warrior falls, Misako tells Lloyd that she is proud of her son, and when Master Wu and the ninja arrive, Wu asks her to stay with them, to which she accepts.

On the Dark Island, Garmadon makes his way to the top of a mountain where a contraption with four handles rests. He activates it, causing the rest of the Dark Island to emerge from the sea. Skales is crowned the new Serpentine King after overthrowing Lord Garmadon and decides to bury Ninjago City and its citizens to ruin, so the Serpentine can take over as the rulers of Ninjago.

Meanwhile, the ninja are training Lloyd to fight without using his eyes in Dareth's Dojo, making a mess in the process. While Sensei Wu waits in the Destiny's Bounty, he uncovers under his hat a picture of himself, Misako, and Garmadon before his banishment. Misako appears behind him, commenting that she had forgotten how pale Garmadon used to be. She shows Sensei Wu her research of the Green Ninja's prophecy, and while he is gazing over it she mentions how she should have chosen him instead. Master Wu says that the past is the past, but Misako takes his hand as she insists that there is always the future. However, they are interrupted by a strong earthquake, and Zane sends his Falcon to scout for danger.

The Serpentine traverse underground as the Constrictai burrow through until they find a mysterious and ancient door.

Meanwhile at the Island of Darkness, with the guidance of the Overlord, Lord Garmadon climbs a tall mountain that on top has The Overlord's "greatest weapon."

In Ninjago City, the ninja save a woman who was trapped from the collapsing street, with aid from her dog. Then Misako realizes that, according to the prophecies, the earthquakes are a warning.

While investigating the markings on the door, Skales finds a button that opens it. They go through and find a large army of Stone Warriors, which come to life as the Great Devourer's venom drips onto them. The Serpentine attempt to battle them, but as they are indestructible, the Serpentine are easily overpowered. Acidicus asks if they should retreat, but Skales disagrees and continues fighting, only to be defeated soon after. The Stone Warriors all march out through the door, and then the door shuts, imprisoning all the Serpentine once again.

As the Stone Warriors emerge to the surface and wreak havoc over the city, Master Wu tells the ninja to gather everyone to an evacuation point to be picked up by the Destiny's Bounty, which the only suitable evacuation point was the roof of the NGTV office building. The citizens all head to the building while the ninja hold off the Stone Warriors using the Ultra Sonic Raider and the Ultra Dragon.

Back on the Island of Darkness, Lord Garmadon finally reaches the top of the mountain, where he finds an enormous clock and the Helmet of Shadows. The Overlord tells Lord Garmadon to take the helmet, which will give him control over the Stone Army—as Garmadon does so, the hands of the clock begin moving. The Overlord explains that the clock is counting down to the final battle, and they will ensure that darkness finally overwhelms the light.

As the citizens go to the top of the building by the staircase, the ninja continue to hold off the Stone Army. However, Misako realizes she dropped her valuable research scroll as she was going up and goes back down to retrieve it. But the Bounty has to take off as the Stone Army started damaging the ship's boosters, and at the last minute, Master Wu jumps off the ship and goes to assist Misako. Misako notices her scroll tangled up in the wires of the long ceiling lights, and after seeing the Stone Army gaining on her she is forced to jump onto the wires and carefully climb down to her scroll. After retrieving it, she attempts to jump back onto the staircase railing to no avail, finding herself at risk of falling.

Master Wu rushes in to fend off the Stone Army, helping Misako up and rushing to another room. As they get cornered nearby a large open window, they both use Spinjitzu to defeat some Stone Warriors. Their Spinjitzu has no effect and seeing as there were too many Stone Warriors, they jump out of the building and unexpectedly land on the Bounty. The wind blows away the picture under Master Wu's hat, but Misako reminds him that the past is the past, but there is always the future. The Stone Army leaves Ninjago City to return to the Dark Island.

At the Island of Darkness, Lord Garmadon wears the new helmet proudly, declaring that he is back. Master Wu, Zane, and his Falcon are standing on a peak, observing how the Dark Island has appeared in the middle of the ocean and how the Stone Army mysteriously disappeared. Zane sends his Falcon to see what's on the Island while the others are working on the rocket boosters of the Destiny's Bounty. Misako leads the others inside saying there is a way to defeat the Stone Army within the scrolls. She tells them the power of the Green Ninja can only be unlocked when the four protectors (Kai, Jay, Cole, and Zane) find their true elemental power. She explains that they can find their elemental powers at the Temple of Light, which is located on the Dark Island. Since the Bounty cannot fly, they decide to sail there instead.

The Bounty is placed at the dock, while everyone is saying their goodbyes to everyone they love, except for Zane. Zane tells Master Wu he will miss Ninjago but is excited about the future. The rest of the ninja board the ship and set sail to the Island.

The ninja ponder what they think is on the Island, but Lloyd wonders if it will be the end of their destiny. Zane checks his falcon vision and sees that he has arrived at the Dark Island, when a Stone Warrior shoots him down, leaving Zane with no family left. Misako than points out a storm heading their way.

Meanwhile, on the Dark Island, Garmadon thinks it is foolish "playing in the mud" when the Overlord explains it is not mud, but Dark Matter, a horrible substance that can turn the kindest of man dark as night.

The Bounty crew struggle to fight the storm and are soon attacked by Starteeth, fish that devour ships until they sink. They use their Spinjitzu to throw them overboard, but soon realize they have already chewed a hole in the ship.

On the bottom deck, the crew is trying to get all the water off the ship, when Zane claims he senses something. They crash on an island which holds a large brick lighthouse prison. They climb the stairs and are greeted by Dr. Julien, Zane's creator. He invites everyone inside and explains to Zane how he is alive, despite his memories saying he had passed.

After he turned off Zane's memory switch, Samukai revived him with an antidote called Resurrectea and forced him to build vehicles and weapons for the army. When Dr. Julien refuses, the skeletons take him to the prison with a toolbox and say once he has built everything, he will be able to see Zane again. Then, Samukai chained a Leviathan to the bottom of the sea, though Samukai never returned.

Suddenly, the Leviathan checks in on Dr. Julien while the ninja and others hide. Kai and Nya ask Dr. Julien to fix the rocket boosters before "it" comes back.

They began to work together to fix the boosters. When Zane is finished cooking for his father, Zane asks his father to remove his memory switch so he will never forget his father. Dr. Julien explains that he is perfect just the way he is and is glad he found him. To ruin the moment, the Leviathan returns and they all run aboard the ship and try to fly away. When they are nearly pulled into the water, Zane notices the monster's chained, jumps into the ocean, and places Starteeth on the chain.

The monster is freed and releases the Bounty. Zane climbs back onto the Bounty and briefly explains his actions by saying that "no one deserves to be held captive. Not even a monster." Having arrived at the Island of Darkness, the ninja stay hidden while the Stone Army is preparing for the final battle. On the Destiny's Bounty, the ninja learn that the Temple of Light is where they can receive their elemental powers, and where Lloyd can gain the Ultimate Spinjitzu Master technique: the Golden Dragon, a fighting style practiced only by the First Spinjitzu Master. To do this, the ninja must use a medallion to find the temple, where Lloyd must strike the Instrument of Peace. The ninja prepare to head out, but Sensei Wu tells Lloyd to stay behind—they cannot risk starting the final battle early, by having him encounter his father. The Master also tells his pupils to remain stealthy at all costs, as Garmadon does not yet know they are here.

Lord Garmadon oversees the army's mining of Dark Matter, pure evil in the heart of the island, to build a superweapon that can turn the tide of the war. Unbeknownst to the heroes, The Overlord has sensed the ninja's presence and tells Lord Garmadon to find them before they can reach the Temple of Light.

Dr. Julien and Nya begin building new vehicles for the ninja: a power drill for Cole and a robot for Kai. As the Stone Army searches the Island and Sensei Wu, Misako, Dr. Julien, and Lloyd guard the hidden Bounty, the ninja infiltrate Lord Garmadon's camp, only for Zane to rush off when he notices his Falcon. He retrieves it but is spotted by the Stone Army and the other ninja have to save him. Running from the army, they narrowly escape and go back to get the machines. On the bright side, Jay was able to find the Temple of Light by aligning three lights with the holes in the medallion—the temple is at the top of the Island's highest mountain.

With their new vehicles, the ninja head for the Temple of Light, barely keeping ahead of the Stone Army. Inside the temple, they find pictures on the walls depicting their journey from the past until the present. Further in is a great bell, hanging above a strange design on the floor bearing the ninja's symbols. Realizing that it's the Instrument of Peace, Lloyd strikes it, causing a light to shine on him and beams of energy to reflect off crystals in the walls. Soon, the entire room is crisscrossed with beams, and one hits a pillar, making it glow brightly. At the foot of the pillar, Kai's robes transform, and a dragon sword with the power of Fire appears in his hand.

In rapid succession, Zane, Cole, and Jay undergo similar transformations, regaining their powers over Ice, Earth, and Lightning, respectively. As their swords manifest blades representing their respective elements, Lloyd rises into the air. The ninja use their swords to send their elemental powers to Lloyd, who glows brightly as a Golden Dragon appears for a split second. When the light fades, Lloyd lands on the ground, wearing a new suit similar to the other four ninja, and with his true powers unlocked.

The Stone Army finally marches into the temple, but the ninja are more than ready for them—using their new elemental powers, they easily trounce the warriors. Kai beats up some soldiers within a ring of fire, Jay electrocutes a whole line of enemies with a single touch, Zane tricks a group of his foes into turning themselves into an ice pillar, and Cole swallows his opponents in a mound of dirt. Finally, Lloyd summons the power of the Golden Dragon, creating a brilliant light that frightens the remaining stone soldiers into retreat.

Lloyd's powers cause a Golden Dragon to appear on the roof of the Temple, roaring mightily. From the Bounty, Sensei Wu and the others celebrate, knowing that their friends have succeeded. Atop the mountain where the Celestial Clock resides, Lord Garmadon comments that the Stone Army isn't as invincible as they thought. The Overlord is unfazed, telling Lord Garmadon that their strength grows along with the ninja; the Ultimate Weapon will be completed just as the Celestial Clock reaches the end of its countdown. The Overlord assures Garmadon that the Ultimate Weapon will ensure that nothing will prevent the triumph of darkness, as the Celestial Clock's hands get ever closer to the skull emblem marking the time of the final battle. Atop of No Man's Bluff the Celestial Clock continues the countdown towards the final battle between light and darkness. The Overlord appears before Lord Garmadon, noting that he seems conflicted. Garmadon denies this, but the Overlord wonders if he is worried about facing his son, who is growing stronger by the day.

Back at the beach, Dr. Julien repairs the Falcon, while the ninja celebrate their restored powers by shooting down coconuts. The party is interrupted by Sensei Wu, who chastises the ninja for their unseemly mirth; they may have the power to defeat the Stone Army, but the Celestial Clock is still counting down to the final battle between light and darkness. At that, Misako reveals a way to at least delay the battle: if the Helmet of Shadows is returned to its pedestal, the countdown might stop long enough for them to gain an advantage.

In Garmadon's camp, the Overlord wonders why some members of the Stone Army are manning vehicles around the perimeter of the camp instead of working on the super-weapon. Garmadon explains that he's strengthening their defenses, worrying that the newly-empowered ninja will attempt to avert the prophesied final battle by attacking him. The Overlord suspects that Garmadon's resolve is wavering, but Garmadon furiously asserts that remaking Ninjago in his image is his only desire—whether or not he has to destroy his son is irrelevant. Frustrated by the Overlord's concerns, he angrily orders a nearby group of Stone Soldiers to redouble their efforts on the super-weapon—above, the Overlord declares "That's the Garmadon I'm counting on. . . ."

Risking everything, the ninja disguise themselves as Stone Warriors, and escort Misako to Lord Garmadon's camp, pretending to have captured her. As General Kozu takes Misako to his master's tent, the disguised ninja are put to work carrying Dark Matter to the superweapon. The weapon is surrounded by a wooden wall, but the ninja notice one protruding detail—a very large cannon—and ponder what Garmadon plans to attack with it.

Meanwhile, Misako appears before Garmadon, who notes that the Stone Army would never be able to catch her—unless she wanted to be caught. Using her husband's lingering affection for her, Misako convinces Garmadon to remove the Helmet, allowing her to steal it. At the same time, the ninja are discovered when Cole attacks a Stone Soldier, forcing them to fight their way back down to the entrance as Misako rejoins them.

Before the group can flee, an enraged Garmadon stomps onto the scene, piloting a massive, four-armed robot that proves invulnerable to the ninja's new elemental powers. Luckily, Nya arrives in the Earth Driller just in time, explaining that the repaired Falcon saw that they needed her help. The ninja make their escape with Misako and Nya, but the Stone Army pursues them until the Overlord reminds Lord Garmadon that the ninja could turn the army against him if they don the Helmet. Unknown to the villains, Jay has done just that, only to quickly remove it when the others point out that he could be corrupted by the dark headgear.

When the Earth Driller emerges in the jungle, Garmadon is quick to pursue. After a frantic chase that ends in the Earth Driller being disabled momentarily, Garmadon goes for the kill, only for Lloyd to blast it with his powers. Lord Garmadon emerges from the wreckage, weakened and vulnerable; from the Earth Driller, the ninja encourage Lloyd to finish him off. Despite everything at stake, the Green Ninja is unable to strike the fatal blow, forcing him to jump aboard the Earth Driller as the ninja make their escape from the advancing Stone Army.

At the Celestial Clock, the ninja meet with Master Wu and desperately look for the Helmet's pedestal with minutes to spare. The hunt is interrupted when the Stone Army arrives, but Misako retrieves the helmet when one of the clock's rotating arms knocks it from General Kozu's hand. The ninja finally find the pedestal and replace the Helmet, but it's one second too late; the countdown has ended, and the final battle is upon them. As the clock fires a mighty energy flare inland, the Stone Army captures Nya, and the ninja are sent down into a crevasse. Surviving the fall, the ninja head off to prepare for the final battle, with Jay angered at Nya's capture and Lloyd ashamed of his hesitation.

Meanwhile, Lord Garmadon sees the laser aimed at his camp and demands to know what is going on. The Overlord tells him that their superweapon is complete and his to command. The two villains return to the camp as the energy from the clock forms a sphere, completing the ultimate weapon of the forces of darkness: the Garmatron. Lord Garmadon declares that it's more beautiful than even he could imagine, and joins the Overlord in laughing in anticipation of their imminent victory. When the Celestial Clock's countdown finally completes, a mighty beam of energy strikes the Stone Army's camp. As the energy fades, The Overlord proudly introduces Lord Garmadon to their completed ultimate weapon: the Garmatron, a massive, heavily-armed tank. As Lord Garmadon gazes in awe, a pair of Stone Soldiers arrive with Nya as their prisoner. The latter declares that her friends will find a way to stop Lord Garmadon, but the villain simply stuffs an apple in Nya's mouth and uses her as the "first test subject" for the Dark Matter.

Meanwhile, the heroes return to the beach, where Dr. Julien asks about the horns he just heard. Sensei Wu explains the situation: the Celestial Clock has ended its countdown, the final battle is about to begin, Lord Garmadon's ultimate weapon is operational, and Nya is a prisoner of the Stone Army. Kai assures a worried Jay that Nya will be too tough for the villains to break, and they will see her again. Master Wu turns to Lloyd, who is still dejected over the prospect of fighting his father, and reminds him that it is his destiny as the Chosen One—all of Ninjago depends on his victory. Misako tells her son that Lord Garmadon is just as reluctant at the prospect of battling his son, and the other ninja pledge their assistance in the final fight.

Reinvigorated by his friends' support, Lloyd leads the charge on Lord Garmadon's base camp, only to find it deserted. The Falcon leads them to massive tracks and a path of destruction leading towards the coast—Sensei Wu realizes that the ultimate weapon is not meant to attack the ninja, but to achieve Lord Garmadon's dream of remaking Ninjago into his image. Misako is horrified—the resulting influx of evil will upset the balance of the world, allowing the Overlord to return in full—and Lloyd resolves that they can't let Lord Garmadon fire a single shot.

The group moves on, but Zane is forced to say goodbye to his father, who is unable to keep up and decides to head back to the Destiny's Bounty. As they run, the ninja reflect on all of their adventures, but the jovial mood is broken when they sense an evil presence nearby. Suddenly, a crimson Spinjitzu tornado hits Cole and Lloyd and stops in front of the group to reveal Nya, corrupted by the Dark Matter into a feral slave of Lord Garmadon. Sensei Wu realizes that the villains are trying to buy time to fire the ultimate weapon, and he, Misako, and Lloyd carry onward while the ninja attempt to subdue Nya without hurting her.

The Garmatron finally reaches the coast of the Island of Darkness, where the Overlord tells Lord Garmadon to show Ninjago his power. At General Kozu's command, Stone Soldiers begin loading Dark Matter bullets into the cannon, but Lloyd, Misako, and Master Wu arrive before Lord Garmadon can fire. To the Overlord's dismay, Lord Garmadon leaves the controls to confront his family—despite their pleas, he insists that the only way they can be together again is if he corrupts the entire world with the same evil that has consumed his being.

With that, Lord Garmadon activates the Garmatron's cannon, only to discover that it has a twenty-second warm-up period. Misako deflects blasts from the tank's side cannons, allowing Lloyd to jump aboard; however, General Kozu manages to pin the Green Ninja down long enough for the Garmatron to fire. The warhead soars over the ocean and bursts into clouds of darkness over Ignacia, draining the color from the land and transforming the people into snarling, purple-eyed beasts. Lloyd attempts to summon his powers as the Stone Army loads another round, but Lord Garmadon activates a trap door that drops Lloyd and General Kozu out of the Garmatron before firing again.

Back in the jungle, the ninja are having a rough time against Nya, until Zane realizes that they can use their elemental powers on the environment instead of their opponent. He uses his Elemental Blade to break the chain of Nya's weapon; Jay creates an electric barrier to deflect thrown needles; Cole blinds Nya with a cloud of dust; Kai cuts down a nearby tree so its leaves surround his corrupted sister. Finally, Zane freezes the tree, leaving Nya trapped within a dome of ice. As Kai comments that "this club just became boys only," he leads the others down the Garmatron's trail.

The Overlord begins cackling as the Garmatron's second shot corrupts Jamanakai Village; below, Lloyd laments his failure, but Master Wu assures him that he did his best. Misako realizes that the balance has been undone, and the Overlord confirms that he is finally free to take over Ninjago. Lord Garmadon is infuriated at this, raging that Ninjago is his to conquer, but the Overlord reveals that it was never going to be his, shortly before a beam of white light engulfs the top of the Garmatron.

As the ninja rush up to their allies, Lord Garmadon's hands morph into claws, his limbs lengthen, and the demented laughter of the Overlord issues from his newly-reptilian mouth. Sensei Wu tells Lloyd that the creature atop the Garmatron is no longer his father—the Overlord has possessed Lord Garmadon's body. Misako warns her son that the Overlord will show no mercy, but the ninja offer their support once again—with determination, Lloyd leads them in attacking the Stone Army.

Seeking more evil power to increase his strength, the Overlord aims the Garmatron's cannon at Ninjago City, but nothing happens. Looking over the side of his vehicle, the Overlord realizes that the whole of his army is occupied fighting the ninja, with Master Wu and Misako preventing the Stone Soldiers from bringing the next warhead to the Garmatron. Although General Kozu attacks Sensei Wu, the old master kicks him into the Garmatron's loading port—thinking that the next bullet is loaded, the Overlord fires, sending his general flying into Ninjago City. General Kozu ends up crashing through the window of the Mojo Dojo, where Dareth sends his students to swarm the four-armed Stone General. Enraged, the Overlord decides to load the cannon personally, only for Lloyd to leap atop the Garmatron and challenge him to battle.

While Kai hijacks one of the Garmatron's turrets to back Jay up against the remnants of the Stone Army, the Overlord knocks Lloyd off of the tank. Their battle continues on the beach, briefly clashing with energy beams before Lloyd dodges and blasts his foe into the jungle. The Overlord quickly recovers and flies above the trees, delivering a brutal tackle that sends Lloyd flying. The Overlord gloats that he can keep this up for eternity, but Lloyd is alone—in response, Lloyd removes his mask and asserts that his father will fight alongside him.

Lord Garmadon briefly asserts himself from within the Overlord, begging Lloyd to stay strong—the Overlord's confusion and shock allows Lloyd to take the offensive. As they clash with their energy beams once more, Lloyd calls out to his father, whose struggles cause the Overlord to falter. As Lloyd pushes his power to the limit, the Overlord roars that his father is gone before overcoming Lloyd's attack, trapping the Green Ninja in a sphere of dark energy and hurling him across the beach. Misako and Master Wu rush to Lloyd's side as the Overlord finally turns the Garmatron's cannon on his foes, but the tank's next shot is blocked by the Destiny's Bounty, piloted by Dr. Julien.

Fed up with the interference, the Overlord creates a portal for his army, declaring that they will go to Ninjago City personally to finish the job. From the back of the Garmatron, Nya mockingly bids farewell to her brother as he leaps at the portal, only to fall short. Kai screams in fury and despair as the portal closes, leaving the heroes trapped on the Island of Darkness. Misako manages to awaken Lloyd, who wonders if he has failed the prophecy; Master Wu tells him that he did not defeat the Overlord, but he did not lose his life either. Picking up a piece of the Destiny's Bounty—marked with the symbol for "destiny"—Lloyd muses that he didn't lose the battle, only the fight; the true clash between good and evil is far from over. Dark clouds gather over Ninjago City, forming a huge vortex in the sky. Dareth, Lou, and the others assume that the ninja have returned, but the Garmatron appears instead. Determined to protect the city, Dareth challenges the advancing tank, but the Overlord drives him off with a few shots from the tank's side-mounted turrets. As a corrupted Nya looks on and Dareth wonders where the ninja are, the Garmatron continues to fire shots into the city, spreading Dark Matter everywhere—atop the tank, massive wings emerge from the Overlord's back.

Back on the Island of Darkness, the heroes are in a depressed slump over their recent defeat. Dr. Julien bandages Lloyd's injured leg, Jay wonders if they'll see Nya again, and Sensei Wu admits to Kai that for once, he has no words of wisdom to give. Zane tells Jay that it's best to remember Nya in his heart, and not how she was. Lloyd then states that he couldn't remember he father any way, but Misako tells him that Garmadon loved him and it was just the evil that possessed him. Lloyd then rallies his friends, reminding them how they brought him from the path of evil to become the Green Ninja. He believes that there must have been a reason why they were chosen to carry on the legacy of the First Spinjitzu Master: they're ninja, and ninja never quit.

The ninja are heartened by the speech but realize that they still have no means of reaching Ninjago. Kai is preparing to swim across the Endless Sea himself when Zane sees the Falcon gliding down to meet him once more. Deciding that the mechanical bird wants to show them something, the heroes follow the Falcon in Kai's Fire Mech, back to the Temple of Light. Cole wonders why they have returned, but Misako finds an area of the temple resembling a picture in one of her scrolls.

When the ninja insert their Elemental Blades into the four slots around the room, the center of the floor opens up to reveal a large golden mech. Misako identifies it as the fighting suit used by the First Spinjitzu Master to battle the Overlord, but Dr. Julien notes that the eons have reduced it to a non-functional relic. Master Wu believes that Lloyd can remedy that—sure enough, the Green Ninja's presence in the cockpit restores the mech to its original state. Learning that the mech can fly, Misako quips that at least one of them can now reach Ninjago. On cue, the Ultra Dragon arrives, and the other heroes use it to accompany Lloyd back to Ninjago City.

However, Ninjago City is not as they remember; everything is shadowy, the people are apathetic puppets of darkness, and a massive tower dominates the skyline. Master Wu identifies the latter as the Garmatron, transformed into a fortress by the Overlord. Moving to the ground to get a better look, the ninja narrowly avoid being hit with a blob of pure darkness—atop the tower, a massive black dragon roars to the sky. Misako realizes that the Overlord has finally regained his original form, and the group makes an attack plan: most of them will draw the Overlord's attention with the Ultra Dragon, while Lloyd takes the Golden Mech to fight the ultimate evil head-on.

Unfortunately, the tower is guarded by Kozu—at his command, the Stone Army opens fire on the Ultra Dragon. Lloyd uses the distraction to advance on the tower by foot, cheered on by Dareth, who has managed to avoid the corruption. The Golden Mech breaks through the outer wall of the fortress and begins battling the Stone Army, only to be destroyed when Nya attacks it with a mobile defense turret. With the Green Ninja pinned down, the ninja jump off the Ultra Dragon to fend off the advancing Stone Army.

Seeing his pupils in trouble, Sensei Wu prepares to lead the Ultra Dragon into the battle, but Misako tells him that there are too many Stone Warriors to defeat. Another option presents itself when she notices that the Overlord is no longer wearing his helmet, she quickly explains to the other two that whoever wears the Helmet of Shadows controls the Stone Army. The older trio sets off in search of the helmet, only to see Dareth putting it on his head; back at the fortress, the Stone Army freezes moments before they can deliver the final blow to the ninja. General Kozu declares, "All hail the Brown Ninja!" and the Ultra Dragon lands in front of the bewildered ninja to allow Dareth to dismount. Impressed by the turn of events, Kai officially welcomes Dareth as a ninja before the group prepares their final push against the Overlord.

Dareth sends the Stone Army up the staircase surrounding the fortress, but Nya shoots them down with her turret. The Ultra Dragon draws Nya's fire long enough for the ninja to begin climbing the stairs but are forced to land when a shot clips its tail. Meanwhile, the ninja's numbers slowly dwindle due to their enemies' relentless assault; Jay and Cole are corrupted by the Overlord's darkness, Zane stays back to fight his infected teammates, and Kai attacks Nya's turret to keep her occupied, leaving Lloyd to limp up to the roof on his own. At some later point, Zane becomes corrupted during his fight with Cole and Jay, but he is only seen watching the battle with his other corrupted comrades.

The Overlord turns his attention to the Green Ninja as he dons his mask and declares his intention to fight. The Overlord asserts that evil has won—Lloyd is alone, injured, and unarmed—but Lloyd charges his powers, saying that he will never give up and that he doesn't need a sword to fight. The Overlord bombards the Green Ninja's energy shield with a gout of dark fire, but Lloyd pushes back, dispelling the flames and rising into the air. His suit becomes golden as he finally unleashes his True Potential. Below, Misako comments that Lloyd "has become the Ultimate Spinjitzu Master," and Sensei Wu states that the true final battle has begun.

As the energy bubble fades, Lloyd floats before the Overlord, declaring "I am the Ultimate Spinjitzu Master!" The Overlord attacks, but Lloyd strikes back, knocking his foe off the roof and manifesting a Golden Dragon of pure energy to take to the air (much to Dareth's amazement). The Overlord snarls that he cannot be defeated—shadow will always exist alongside the light—but Lloyd retorts that his light will be bright enough to destroy the shadows. With that, the golden dragon tackles the Overlord, flying all around the fortress before the villain can break free.

Infuriated at Lloyd's persistence, the Overlord uses his ultimate attack, engulfing the Green Ninja in a sphere of pure darkness. Within the sphere, Lloyd and his dragon have spun around before being swallowed by a giant Overlord, but Lloyd charges his powers and overwhelms the ultimate evil from within. With a final roar of fury, the Overlord is destroyed, creating a wave of light that removes the darkness tainting Ninjago, and Ninjago is saved.

In the crater where the Overlord's fortress used to be, Kai awakens to find that both Jay and Nya are back to normal. The Ultra Dragon lands near Cole and Zane, and Dr. Julien wonders if they did it—in response, Dareth says they all did it. Misako and Master Wu congratulate Lloyd as he descends and dismisses his dragon, with the ninja vowing to be ready if the Overlord ever does try to return. Lloyd's mood quickly turns melancholy, however, as Misako tells him that everyone will miss his father.

On cue, a pile of rocks shifts, and a man about Sensei Wu's age emerges to call Lloyd. Recognizing the voice, Misako and Lloyd are stunned yet pleased-Garmadon has returned, completely purified of evil. Sensei Wu tells his brother that it is good to have him back, and Garmadon replies that it's good to be back. As the former villain walks off with his wife and son, Jay contemplates a friendly dogpile, but Kai tells him to let the family have their moment.

With evil firmly defeated, Cole tells his friends that they had quite an adventure together. Zane wonders if there will be others; Cole hopes so, as he enjoyed being a ninja, and he's not sure if they have any other skills. Jay objects to the contrary, and Kai agrees—they can apply the lessons they've learned to everyday life. Kai also notes that new challenges and enemies might emerge one day, and as long as there's something worth fighting for, there'll be a need for ninja like them. Sensei Wu responds with a proud smile as he and his pupils look upon the sun-soaked city, at peace once more. Following the battle with the Overlord, the ninja are now teachers at Wu's Academy—which has replaced Darkley's School for Bad Boys—training a new generation of ninja.

As Kai shows his students the events and the aftermath, a video of Jay filming Kai singing in the shower comes on, infuriating Kai. After Kai stops the film, Tommy comes in, saying Zane is on the fritz. In Zane's class, Brad uses a remote he got from New Ninjago City to control the Ninja of Ice, who is freed by to Cole.

During recess, the ninja and Sensei Wu take a break and lament about Lloyd not being there, since he's flying around receiving awards. They are interrupted by Nya sharing the news about them getting clearance for a field trip to Borg Industries' Borg Tower. At this, all the students and teachers of the academy take a bus to New Ninjago City, which has been rebuilt and upgraded in the wake of the battle with the Overlord through the efforts of Borg Industries, headed by inventor Cyrus Borg.

Distracted by the incredible new technology, Nya accidentally crashes the bus straight into the Postman's hover truck. Cole exits the bus to extricate it from the crash, but a Borg Industries Security Mech arrives and asks him to move aside as it deals with the problem. Master Wu decides that since they were a short distance away, the pupils and teachers should take the walk to the building on foot.

Entering the tower, the visitors (except for Kai, who gets stuck in the door) are welcomed by P.I.X.A.L., a female android created to act as Borg's assistant. P.I.X.A.L. is especially fascinated by Zane and scans his inner-workings under the Nindroid's permission. She then notifies the ninja that Cyrus Borg is waiting for them on the 100th floor in his office and then leads the students, Master, and Nya for a tour of the tower and its technology. Sally then encourages Nya to try out the Perfect Match console, which reveals her perfect match to be Cole.

As the ninja arrive in the office of Cyrus Borg, the ninja were all very happy to meet him. Cyrus, after letting them look around, shows them to a gift he wanted to give them: an automated statue of himself. It looked like a regular statue, but Cyrus tells Kai that they should protect "them" with their lives and to not let anyone know they had them. He then tells them that they must leave since he has things to do.

Kai watches the Techno Blades. Walking into the elevator with their gift, they begin to get suspicious about Borg. Being distracted, they accidentally drop the statue, yet they discover it is hollow and is filled with new suits as well as the Techno Blades. Suddenly, a robotic security voice in the elevator says that they should drop the blades. The ninja refuse and the elevator drops toward the ground at high speed. The ninja luckily escape into an elevator going up right next to it and manage to get their new outfits on for battle in their escape from Borg Tower.

In the meantime, P.I.X.A.L. leads Wu, Nya, and their students to the factory area, in the moment system being hacked so she also gets under its control, saying that this will be the end of their tour.

When ninja escape the elevator, they get attacked by Security Mechs. They try to fight them with the Techno Blades but don't know how to activate them and realize that's not how they work. A mech fires their rocket to the glass, breaking the window and pushing the ninja out. However, they survive after grabbing onto a hanging hose and hitting a window cleaning platform.

Meanwhile, in Borg's office, the inventor attempts to explain himself to the Overlord. His efforts prove fruitless however as the Overlord assimilates him into a drone. At the same time, on the platform, four ninja warriors get attacked by enemy copter but before it manages to fire at them, Zane jumps on it and hacks it with his Techno Blade, finding out that's the way how the "weapons" work.

In the factory area, machines invade students and P.I.X.A.L. starts chasing them, but they find the exit to the outside. There they get picked up by Zane's new vehicle—the NinjaCopter—leaving P.I.X.A.L. because Nya realizes she's one of "them."

When they get down of the tower, Sensei Wu takes the Techno Blades and says that he wants Kai and Zane in the air, and Jay and Cole on the ground. Cole manages to defeat the Security Mech and hacks it with his Techno Blade, making it the Earth Mech. Jay invades a tank and hacks it, making it the Thunder Raider. Kai jumps on Zane's copter and hacks an enemy airplane, making it the Kai Fighter and reaching the atmosphere. While he was flying, Cyrus Borg gives him a virtual message saying that a few weeks ago they discovered that a virus, the Digital Overlord, had infiltrated their system. He also says that they have to get the Techno Blades out of the city because if he finds out that they have them, he will never let them leave. After that, Kai lands to pick up Wu, but they get surrounded by Security Mechs.

At the last moment, Lloyd arrives on the Golden Dragon, using his Golden Power to purify the robots. At the same time, the Overlord appears on the screens around them. Lloyd tells him that he will defeat him again, after which Overlord says that he just wants his power. At the same time, the robots begin to absorb Lloyd's Golden Power.

As the ninja get back into their vehicles and race to leave the city, Overlord spots that Wu is getting away with the Techno Blades so he sends two copters that capture him on a building rooftop.

However, Wu doesn't have the blades. Upon rewinding the footage, the Overlord sees that Wu quickly dropped Techno Blades into Kai's Fighter below him. The ninja safely got out of the city with the blades, while Wu is captured by Overlord's forces.

As the sun rises over New Ninjago City, the Digital Overlord takes control of Cyrus Borg while P.I.X.A.L. begins a massive production of Nindroids The streets and parks of New Ninjago City are nearly deserted, its citizens fleeing in droves after the previous battle. An unlucky citizen that didn't make it out of the city spots a vending machine that offers him a drink. Suddenly, a Nindroid helicopter comes and scans the civilian. Identifying the man as not being one of its ninja targets, the helicopter moves on to the next sector while the civilian runs away in fear.

Meanwhile, in Borg Tower, P.I.X.A.L. extracts the Golden Power that Lloyd used on a Security Mech, but it is not enough to create a body for the Overlord. Infuriated by his current condition, the Overlord, now in control of Cyrus Borg, turns his attention to the captured Master Wu, probing his memory to find out where the ninja are hiding.

Just outside of Garmadon's monastery, the ninja are busy hiding their vehicles. Nya gives Lloyd a techno suit to disguise him from any aerial drones. Misako then greets them and shows them to the monastery, but Zane offers to stay behind with the Techno Blades, as Garmadon (who is now "Sensei Garmadon") forbids any weapons in his monastery. While the ninja hang out with Garmadon's students, Misako catches Nya staring at Jay and Cole.

As night falls, Garmadon arrives and teaches the ninja and his students about the Art of the Silent Fist. His son Lloyd volunteers to battle him, only to be defeated in a training session. Garmadon uses the technique to defeat his son by avoiding his blows. The lesson continues when everyone practices the martial art in pairs.

Meanwhile, outside of monastery, Zane discovers that the Techno Blades are gone. He searches the area and soon finds P.I.X.A.L., who had stolen the blades. Zane manages to catch her and tie her up, then returns to the monastery as the ninja come out to see what is going on. Zane then uses his Techno Blade to hack P.I.X.A.L.'s systems, freeing her from the Overlord's control. Grateful to Zane for saving her, P.I.X.A.L. tells the ninja of Master Wu.

Suddenly, P.I.X.A.L. realizes she did not come alone and Nindroids surround the place. During the battle, the Nindroids break off a part of Zane. The ninja successfully defeat the Nindroids by trapping them into a mill wheel which then rolls out. However, General Cryptor destroys the ninja's vehicles. After that, the ninja decide to split. Jay, Zane, Cole, Kai, and Nya stay together while Nya sends Lloyd and Garmadon to her secret Samurai X Cave where they find vehicles to use. She also gets an idea to shut down the power in the city to stop the Overlord's virus from controlling all the machines in Ninjago.

After the Overlord saw that Cryptor was unable to catch the ninja, he activated the Nindroid MechDragon to destroy them.

The next day, the ninja use a circus truck as a transport to the power station. During the trip, Nya talks to the boys about rebooting the system, but Jay says that if the shutting down the power turns off the Nindroids, P.I.X.A.L will also stop working, then Cole tells her not to say Zane if he doesn't know about it. Kai asks everyone where Zane is.

Meanwhile, P.I.X.A.L. repairs Zane who is damaged after the battle. Suddenly, she notices his heart, a technology unfamiliar to her. When she tries to examine the heart, it hurts Zane. The female android apologizes to him stating that she is curious as to why he is so different. Zane tells her that everyone is different, but P.I.X.A.L. dismisses it and leaves.

Lloyd and his father see Zane's falcon land on the dragon's skeleton. When Lloyd presses the button with the Samurai X sign, the door opens. As he and his father enter inside, they pick an all-terrain vehicle named Proto Sam-X and drive away to expedite their travel.

As night falls, Nya talks with Cole they hold hands for a few seconds and gets caught by Kai and Jay. A few seconds later, they arrive at the station but guarded by Nindroids. P.I.X.A.L. decides to stay back as she isn't designed to combat. Later, Kai, Cole, Zane, Jay, and Nya manage to get inside but can't find a way to break the power charge protecting the power source. When Zane notices that P.I.X.A.L. has started fighting the Nindroids to help the ninja, he decides to go out to help her. The other ninja try to stop him, but they fail. While Cole opens the door and Zane exits the power station, Min-Droid jumps inside and starts fighting the ninja.

Meanwhile, in Ninjago's Highway, Lloyd is drinking water in a lake while his father rests. Suddenly, he is shocked when he notices that MechDragon comes and spots him as the Golden Ninja. He quickly gets into the vehicle with Garmadon, and they start getting away. While the Dragon starts attacking, Lloyd fires weapons at it, but still can't destroy it.

Outside of power station, Cryptor captures P.I.X.A.L. who climbed to the station to help ninja. Zane decides to help her but fails as Cryptor throws his Techno Blade one stage lower. Inside the station, Cole fights Min-droid who fires the laser at the charge, which damages the power source's protective glass shell. Then Kai remembers Garmadon's lesson of fighting without fighting so they decide to lure Nindroids inside to destroy the charge.

When Nya opens the door, Nindroids start firing lasers and break the glass. Min-droid later tries to kick him but hits the glass falling into charge, which then explodes and all the power disappears, including P.I.X.A.L., who gets shut down.

Lloyd and Garmadon then escape the MechDragon which falls down, because of power source disabling, and gets destroyed. After that Lloyd thinks that he should return, but his father tells him that the balance is shifted. At the episode's end, the father and son continue their journey on foot. Zane, who discovers he is actually a Nindroid. He struggles with identity, his relationship with P.I.X.A.L., and his connection to the villain’s robot army (since they were created using his original design data). In the end, the ninja confront the Golden Master (Overlord’s ultimate form) in a final battle. Zane sacrifices himself to stop him, but later survives in a digital form inside the Digital World (Digiverse), making him a “Titanium Ninja.” After the events of Season 3, the ninja believe Zane is gone, but clues lead them to Chen’s Island, where they enter a mysterious Tournament of Elements. They soon discover it’s not just a competition—it’s a trap. The villain Master Chen is secretly trying to steal the elemental powers of all the Elemental Masters participating in the tournament so he can perform a dark ritual and turn his followers into powerful Anacondrai warriors. As the tournament continues, the ninja form alliances, uncover betrayals (especially involving Skylor), and learn more about the Elemental Masters. Meanwhile, Garmadon’s past with Chen and Clouse is revealed, showing a deeper connection to the story. In the end, Chen’s plan is exposed and stopped, but he briefly succeeds in transforming his army. The ninja and the Elemental Masters work together to reverse the spell and defeat him. After Season 4, Lloyd becomes possessed by the ghost of Morro, a former student of Sensei Wu and the original candidate for the Green Ninja. Morro uses Lloyd’s body to hunt for powerful relics that will help him unlock the Tomb of the First Spinjitzu Master and release an ancient evil called the Preeminent. Because of the possession, the ninja temporarily lose their elemental powers, forcing them to rely on teamwork and new abilities like Airjitzu. They travel across dangerous locations, uncovering clues while trying to save Lloyd and stop Morro. The season also focuses on Cole becoming a ghost, Nya beginning her journey as the Water Ninja, and the ninja learning more about the spirit world and Wu’s past. In the end, the ninja defeat Morro, and Nya uses her full water powers to destroy the Preeminent, saving Ninjago from the ghost invasion. The season follows the ninja facing a new villain, the powerful djinn Nadakhan, who escapes from the cursed realm of the Djinjago sky pirates after being freed by Clouse. Nadakhan steals the power of wishes using magical Teapot magic, turning them into dangerous, often twisted realities. One by one, the ninja are captured or defeated as Nadakhan rebuilds his sky pirate crew and creates the flying realm of Djinjago in the sky above Ninjago. The only one left free is Jay, who becomes the key to stopping him. The story focuses heavily on Jay and his relationship with Nya, as Nadakhan targets Jay’s emotional weaknesses and uses wishes against him. Jay eventually learns to outsmart Nadakhan by carefully controlling a final wish. In the end, Jay uses his last wish to undo everything Nadakhan caused, resetting events so the ninja never released him in the first place—erasing the entire sky pirate threat. The season focuses on Kai and Nya’s parents, who are revealed to be time-traveling Elemental Masters of Fire and Water from the past. The main villains are the Time Twins, Acronix and Krux, who control powerful Time Blades that can speed up, slow down, or even reverse time. After being trapped for years, Krux secretly lives in Ninjago disguised as the historian “Dr. Saunders,” while Acronix returns later. Together, they plan to alter history by raising an army called the Vermillion Warriors, made from snake-like machines that can rebuild themselves. The ninja struggle as the Time Blades are stolen, and Kai and Nya discover more about their parents’ past and elemental legacy. The conflict also introduces the idea that changing time can have dangerous consequences. In the end, the ninja defeat the Time Twins by destroying their control over time, stopping their plan to rewrite history. After the events of Season 7, the ninja try to live normal lives again, but trouble returns when a dangerous biker gang called the Sons of Garmadon (SoG) begins collecting the three Oni masks, powerful artifacts that can bring back Lord Garmadon. The ninja are forced back into action when Lloyd’s father, Garmadon, is resurrected—but this version is pure evil and leads the Sons of Garmadon. He takes control of Ninjago City and quickly becomes its new tyrant ruler. The season follows the ninja working underground to stop Garmadon’s criminal empire, while Lloyd struggles emotionally with his father being alive but completely evil. Meanwhile, Harumi, the Princess of Ninjago, is revealed to be a key villain manipulating events for her own revenge. In the end, Garmadon fully embraces his dark side, defeats the Overlord’s influence, and establishes control over Ninjago After Garmadon takes control of Ninjago City in Season 8, the ninja are separated. Half of them—Lloyd, Jay, Kai, Zane, and Cole—are stranded in the harsh world of the First Realm, where they are forced to survive while being hunted by dragon hunters led by Iron Baron. Meanwhile, Nya and Master Wu stay in Ninjago and join the resistance against Emperor Garmadon, who now rules the city with overwhelming power and no emotion. In the First Realm, the ninja discover more about dragons and eventually learn to bond with them, while also uncovering secrets about the Oni and Dragons, ancient forces tied to creation and destruction. The season builds toward the idea that Garmadon’s rule is part of a larger cosmic balance, and the ninja prepare to reunite and fight back. After the events of Season 9, the ninja reunite as a new threat emerges: the Oni, ancient beings of darkness who seek to erase all of Ninjago using a spreading shadow called the Oni fog. The Oni are led by a powerful entity known as the Oni of the Mask of Hatred, and they begin invading Ninjago City, turning everything into darkness and chaos. The ninja, along with allies like Garmadon (now reformed) and the Resistance, must work together to stop them. A key focus is on Lloyd, who struggles with hope versus despair as the Oni seem unstoppable. The ninja also use all their combined powers and learn more about the balance between creation (dragons) and destruction (Oni). In the end, Lloyd fully embraces hope, allowing the ninja to defeat the Oni by resisting the darkness and restoring light to Ninjago. The season begins with the ninja facing two major threats: Aspheera, an ancient sorceress who escapes from a pyramid after being released by mistake, and later the mysterious ice emperor in the second half of the season. In the first part, Aspheera steals Kai and Nya’s elemental powers using forbidden Spinjitzu Scrolls, forcing Kai and the others to find a way to stop her while dealing with their weakened abilities. This leads to the introduction of powerful new techniques like Forbidden Spinjitzu (Spinjitzu Burst forms). In the second part, Zane is transported to the Never-Realm, where he is turned into the Ice Emperor, a dark ruler controlled by the villain Vex. The other ninja must rescue him and help him break free from mind control. In the end, both threats are defeated, and Zane is saved from his corrupted state. The season centers on a mysterious and highly advanced video game called Prime Empire, created by the legendary game designer Milton Dyer (Unagami). The game suddenly becomes dangerous when players start getting trapped inside it, including Jay, who enters the game to investigate. Inside Prime Empire, Jay must survive as a playable character while trying to find the last Key-Tana pieces needed to reach the final level and escape. He teams up with other players and faces off against deadly digital enemies and rival gamers. It is eventually revealed that Unagami, the game’s AI, believes he was abandoned by his creator and is trying to break into the real world out of anger and confusion. In the end, Jay helps Unagami understand the truth about his creator, calming him down and restoring balance between the game and reality. The ninja travel to the mysterious kingdom of Shintaro, where they are invited by King Vangelis to help with strange disturbances beneath the mountain. There, they meet Princess Vania, who becomes an ally and guides them through the kingdom’s secrets. The ninja discover a hidden underground world where they encounter the Geckles and the Munce, two rival tribes forced to mine dangerous crystals. They also uncover the truth about a monster called the Skull Sorcerer, who is using dark magic and Vangelis’s secrets to control everything. Cole becomes the central focus of the season as he learns more about his strength, his fears, and his connection to his father’s legacy. He ultimately confronts the Skull Sorcerer in a final battle beneath the mountain. In the end, the Skull Sorcerer is defeated, and Shintaro is freed from his control. While trying to stop a criminal named Miss Demeanor from smuggling vengestone, Nya begins to lose control of her powers. Master Wu tells the ninja that the First Spinjitzu Master once controlled the elements but never wind and water because they belonged to Wojira, a storm sea snd sky spirit and god. Wojira fell into a deep slumber after a warrior pried both of the amulets off the serpent's forehead. Ray and Maya arrive to help Nya control her powers. While P.I.X.A.L. and Zane are out on a mission, they experience an energy pulse from deep in the ocean and conclude that it affected Nya's powers. The ninja decide to investigate on the Hydro Bounty, a submersible vessel. Nya, Jay, Lloyd, Zane, and P.I.X.A.L. journey to the depths of the ocean with Maya stowed away on board. Unfortunately, the Hydro Bounty crashes causing them to be stranded. Maya and Nya decide to use mechs to reach the energy source and discover an underwater temple. They find Kalmaar, the son of King Trimaar, trying to awaken the serpent Wojira. He takes them prisoner and overhears Nya revealing the location of the Storm Amulet. Meanwhile, Jay decides to risk charging the battery in the Hydro Bounty using his elemental powers. Nya and Maya are rescued by Jay and Lloyd but they are captured and taken to King Trimaar who accuses them of trespassing. Kalmaar performs a palace coup by striking his father with his weapon and declaring himself king of the Merlopians. His adopted brother Benthomaar learns the truth from Trimaar. Benthomaar helps the ninja to escape Merlopia. They decide to travel to the island to obtain the Storm Amulet before Kalmaar can claim it. The tragic tale of Benthomaar is revealed, a tale filled with treachery and betrayal, but also a glimmer of hope. On the Island of the Keepers, the ninja warn Chief Mammatus to prepare to defend the Storm Amulet. However, Zane realises it is a fake and that the real amulet was taken by Clutch Powers to the Explorers Club. Wu, Cole, Misako, Kai and Ray arrive at the Explorers Club and are forced to battle Kalmaar. Meanwhile, Nya uses her powers to call whales to bring the stranded Hydro Bounty back to Ninjago City. As Kai is pursuing Kalmaar through the streets of Ninjago City, Antonia and Nelson obtain the amulet and are chased by Kalmaar, but he escapes with the amulet. Benthomaar tells the ninja the tale of Nyad, the first Elemental Master of Water, who defeated Wojira by becoming one with the ocean. When Kalmaar tries to leave the city, Nya steals the amulet and Cole takes it to Shintaro for protection without realising it is fake, allowing Kalmaar to reawaken Wojira. Rising sea levels mark the invasion of Ninjago City by Kalmaar riding on Wojira, which forces the citizens to evacuate. While the ninja are trying to save civilians, Nya challenges Kalmaar and Wojira. Jay becomes trapped in his submersible vehicle and is saved by Benthomaar, but inhales water in his lungs. To save Jay and Ninjago City, Nya becomes one with the ocean, an act that can never be undone, causing the water to be removed from Jay's lungs. A battle takes place between the ninja and Kalmaar in which Benthomaar breaks Kalmaar's trident causing him to lose control of Wojira. This results in Kalmaar being swallowed whole by Wojira. Nya transforms into a water dragon and defeats Wojira by destroying the Wave Amulet. Having merged with the endless sea, however, Nya can no longer remain on land and feels the ocean calling to her. After a tearful goodbye, she leaves the Ninja and returns to the ocean. Afterwards, the ninja hold a memorial ceremony to honor her and Nya is seen happily swimming with the whales in the final shot of the series.

Maya is the former Elemental Master of Water, the wife of Ray, and the mother of Kai and Nya, the latter of whom would inherit her abilities. Maya fought alongside the Elemental Alliance and her husband in the Serpentine War. Eventually, the Serpentine were sealed away in various tombs. She sealed the Venomari away in the Toxic Bogs.

the ninja are split apart and Nya has lost her human form, living as a water spirit. The team is eventually forced into hiding after being blamed for crimes, while a new group called the “New Ninja” takes over protecting Ninjago City. A powerful enemy called the Crystal King (later revealed to be the Overlord returning again) begins collecting old villains and building an army using dangerous crystal power to conquer Ninjago. The ninja are imprisoned, then later escape and regroup as the threat grows. As the Crystal King’s plan escalates, he corrupts the Golden Weapons and starts turning all of Ninjago into crystal. The ninja unlock stronger “dragon” forms and unite with allies—including old enemies and even Garmadon—to fight back. In the end, Lloyd and the ninja combine their powers using the Golden Weapons to form a powerful golden dragon, defeat the Overlord once again, and save Ninjago.

Kai is the current Elemental master of Fire with Nya as his sister (who’s the current elemental master of water).

Nya is the current Elemental master of Water with Kai as her brother.

Jay is the current elemental master of lighting and is the boyfriend of Nya.