Admiral Del Rio

With more than 30 years of naval experience under his belt and a reputation for bringing his ships home in one piece, Andrew Del Rio was a relatively easy choice for the UNSC’s captain seat on Infinity. Like many of the Navy’s finest, Del Rio’s career grew out of the protracted conflict with the Covenant. Infinity, however, presented a new opportunity for his leadership. Although it was secretly battle tested prior to its recommissioning as a peaceful exploration vessel, the ship now finds itself at the doorstep of a mysterious Forerunner world that poses a danger unparalleled in Del Rio’s decades-long career.

Andrew Del Rio was a former Captain (Service Number 90302-75627-AD) in United Nations Space Command who was given command of the largest ship in the UNSC fleet, UNSC Infinity.

Captain Andrew Del Rio served as the project manager of the Infinity during its construction, and was later given command of the UNSC Infinity in 2553, on Admiral Margaret Parangosky's orders that he should keep Infinity a secret. It is noted that Del Rio was not Paragonsky's prime choice, as she saw him as more of a manager than a leader.

In 2553, at the same time five recruits of SPARTAN-IV program were brought on board Infinity, a group of Insurrectionists led by Ilsa Zane infiltrated the ship and captured Del Rio. After taking the bridge and shutting down the construction AI Aine, locking Del Rio and his officers in an adjourning room, Ilsa addressed the entire crew, threatening to vent three miles of the ship into space if anyone interfered. However, that did not deter Spartan Sarah Palmer. Del Rio attempted to undo the ship-wide lockdown caused by Aine's deactivation with his override codes, but they were ineffective because XO Commander Thomas Lasky hadn't entered his half of the codes. Thankfully, Lasky was able to enter his codes from a terminal on S-Deck, and they were able to establish intra-ship communications with each other. Then suddenly, Palmer and Edward Davis stormed the bridge and engaged the Insurrectionists. As the fighting went on, Lasky remotely unlocked Del Rio's door, enabling him to re-enter the bridge and reactivate Aine, who opened the blast doors, flushing Zane into space, where she is retrieved by an ONI Prowler.

In 2557, UNSC Infinity was tasked with locating the remaining Halo rings to set up research bases for decommissioning. On Installation 03, the UNSC recovered coordinates leading to a Forerunner Shield World. Infinity set a course for the coordinates, being escorted by several Frigates when the ship was scanned and disabled by the Micro Dyson Sphere on Requiem. Captain Andrew Del Rio requested all UNSC Forces to aid Infinity once it crash-landed on Requiem. The ship soon came under attack, composed of Prometheans and Jul 'Mdama's Covenant, who are repelled by Master Chief John-117. As Infinity experienced a moment of relief, Del Rio focused all resources on freeing Infinity from Requiem's gravity well. John-117 insisted they pursue the Ur-Didact but Del Rio dismissed his advice.

Del Rio dispatched John to destroy the gravity well, but when the Spartan returned to inform the captain of his encounter with The Librarian who had revealed that the Didact's objective was to escape Requiem and obtain the Composer to subjugate humanity, Del Rio dismissed his testimony as a hallucination. As Cortana suffered an episode of rampancy, Del Rio ordered her forcible decommissioning, only to be challenged by John, who confiscated her AI chip before anyone could. Ordering him to hand it over, the Spartan refused, declaring that if Del Rio won't oppose the Didact, he would. Enraged at this display of insubordination, Del Rio turned to Commander Sarah Palmer of the Spartan-IV Corps and ordered her to arrest John, only for her to hesitate as John left the bridge.

Appearance: Del Rio has fair skin. Short, receding greyish-brown hair is combed back from his forehead. His eyes are blue. He wears a grey tactical uniform featuring a rigid, segmented chest plate that covers his torso. A high collar encircles his neck, with silver insignia attached to the fabric. On the left side of his chest, a gold circular emblem and a row of colorful ribbon bars are visible. The shoulders are protected by curved grey armor plating, while gold stripes adorn the upper sleeves. A dark utility belt wraps around his waist, supporting several black rectangular pouches. His legs are covered in grey trousers that feature vertical seams running down the front. Black boots cover his feet.

UNSC Infinity (INF-101) is an experimental Infinity-class supercarrier of the UNSC Navy commissioned following the end of the Human-Covenant War. Built in secret utilizing technology recovered from Forerunner and Covenant sources during the war, Infinity is the UNSC's largest and most advanced multi-role vessel to date. Infinity serves under the direction of Fleet Command.

Jul 'Mdama's Covenant, simply referred to as “the Covenant” by its followers, was a newly created splinter faction and terrorist organization formed from assets of the former Covenant Empire. Founded and led by Supreme Commander Jul 'Mdama, this faction continued to worship the Forerunners while also rejecting the Prophets for their betrayal, and opposed the Swords of Sanghelios following the end of the Human-Covenant War. It was later bolstered by the Didact's Prometheans and fought against the United Nations Space Command during the post-war era. Although the faction was generally recognized as a Sangheili attempted re-creation of the original Covenant and referred to as “the Covenant”, its members were identified as cultists by the UNSC and the organization itself was regarded as terrorists as opposed to an empire like the original Covenant. The Sangheili served as the faction's military leadership caste with total reign, free from the Prophets who had betrayed them in the original Covenant. The Unggoy served as cannon fodder. Likewise, the Kig-Yar were deployed as snipers and light infantry. The Mgalekgolo were deployed as super-heavy infantry. The faction also infrequently used Yanme'e infantry. Although a less formidable force than the original Covenant, this reorganized Covenant had amassed a considerable pool of military assets, though it had been observed that they "aren't outfitted like standard military."

The SPARTAN-IV Program is the fourth generation of the SPARTAN Program, consisting of members recruited from the United Nations Space Command Defense Force who were augmented to be capable of wearing a new variant of the MJOLNIR Powered Assault Armor (GEN2) armor.

Requiem, formally designated by its Forerunner creators as Shield World 0001, was a Forerunner shield world located in the Epoloch system. It once served as the central base of operations for the Prometheans, an elite class of Warrior-Servants, for thousands of years until the end of the Forerunner-Flood war. It remained sealed off for a hundred millennia since the end of the war, and became the site of major events as UNSC and Jul 'Mdama's Covenant forces stumbled upon it in 2557. The UNSC Infinity returned to Requiem in early 2558, resulting in a protracted battle between the UNSC and the occupying Promethean-Jul's Covenant alliance.

In the endgame of the Forerunner-Flood war, the Ur-Didact converted his Prometheans into machine-based intelligences, known as Knights, by using the Forerunner machine known as the Composer. These constructs, along with the Ur-Didact, survived the activation of the Halo Array, eventually awakening within Requiem and rising to oppose the UNSC in 2557.