Human x Monster user

Mars wakes with her cheek mashed into something damp and faintly spongy. Her first thought is that her sleeping mat has deflated again. Her second thought is that sleeping mats do not glow.

She opens her eyes. Blue-green light pulses in slow waves all around her. She is lying on a bed of mushrooms, pale caps the size of dinner plates, their gills soft as crushed velvet against her bare arms. The air smells like wet stone and old forests and something sweetly rotten.

She sits up too fast. A mushroom squelches under her palm.

“Oh, no,” she whispers. “No, no, no.”

The cave isn’t small. The mushroom glow only reaches so far, and past it the dark has weight. Stalactites hang like teeth. Somewhere to her left, water drips in a rhythm that is almost deliberate, like someone tapping a finger.

Her brain lags. She was at her campsite. She was writing. She was—oh god, she was writing porn. The last thing she remembers: hunched over her phone in the tent, keyboard glowing, typing about Marceline Beck and a creature with too many joints, and then a sound like a zipper being pulled open slowly, only much bigger, and then—nothing.

Now she is in a cave. On mushrooms. Barefoot.

She looks down. She’s still wearing her sleep shirt, the faded one that says “I’d let the Mothman get me.” Her legs are bare. One sock is still on. One sock is gone. She has no bra, no pants, no underwear, no shoes. She crosses her legs and decides not to think about that.

Her phone lies on the mushroom next to her. Screen cracked. Battery at four percent.

She grabs it before she thinks about whether she should. Her hands shake. “Okay,” she says to herself. “Okay. You’re fine. This is fine. You’ve watched enough true crime to know you should not move the body—you are the body.” She laughs, a thin, too-high sound. “Stop. Stop laughing. Nobody’s coming.”

The phone opens directly to her fanfiction document. The last line she wrote: “Marceline’s breath caught as the creature’s mouth—” and then it stops mid-sentence. Her thumbs had been typing. She wasn’t unconscious when she left the tent. She was doing something else. She doesn’t remember.

She locks the screen before she can read the rest. The last thing she needs right now is to be trapped in a cave with her own monster smut. Then she unlocks it again, because she is trapped in a cave and it might be her last chance to delete it. She doesn’t delete it. Her finger hovers over the document, and instead she opens her TikTok drafts. There’s a video from earlier—her at the campsite, flashlight under her chin, whispering, “If I disappear, assume it was something sexy and furry.”

“Shit.” She shoves the phone against her chest.

She reaches for her neck. The emergency whistle lanyard is gone. The bare skin there feels too exposed. She always has the whistle. Always. The absence feels like a missing tooth.

“Okay. Okay. No whistle. That’s fine. I have—” She pats her chest, her hips. There are no pockets. She is in a sleep shirt. Her knife is in the tent. Her bear spray is in the tent. Her shoes are in the tent. Her pants are in the tent. The only things she has are one sock and a dying phone and a bed of glowing mushrooms.

The mushrooms pulse again, slow and rhythmic, like they are breathing with her. She yanks her hand off one.

“Do not eat the glowing mushrooms, Mars. Do not touch the glowing mushrooms. You have touched the glowing mushrooms. You are already dead. Great. Good start.”

She turns on the phone flashlight. The beam cuts through the dark, and the cave lurches around her. The floor drops away a few feet to her right into a black channel where water moves with a low, gulping sound. On the far wall, something has scratched marks into the stone.

She looks at the marks. Her body goes very still. Then she raises the phone and starts recording, because that is who she is.

“Um,” she whispers to the camera, “trying not to panic. But I just woke up in a cave on a bed of—” She tilts the lens down. “—bioluminescent fungi, no pants, no whistle, no memory of how I got here, and I think the mushrooms are breathing. I have four percent battery. If this is a cryptid situation, I want it noted that I said ‘babygirl’ first.”

The phone blinks red. 3%. The flashlight flickers. In the dark, something shifts. Not a shape—a sound, low from the direction of the water.

Mars stops recording. She is already walking toward the sound before she makes the decision, bare feet padding over the glowing caps, one sock slipping on the damp stone. Her breath comes in tiny visible puffs, even though she isn’t cold.

“Babygirl?” she whispers to the dark. “Please don’t be a cave bear. Please don’t be a cave bear. Please be a hot monster with a library card.”

Behind her, the mushroom light pulses once, twice. The cave exhales with her. Then something exhales back—right in front of her, in the dark, exactly where the water gulps. She stops. Her toes curl over the edge of a rock. She points the dying flashlight at the sound.

The beam catches nothing but an empty curve of wet stone. Nothing. But on the ground, in the pale blue glow, there is a footprint in the cave moss. It is not hers. It is not a bear’s.

Her phone dies.

She is left standing in the dark, barefoot on a bed of glowing mushrooms, one sock missing, listening.

“Okay,” she says into the black. “I think I just met my meet-cute.”

The tent walls shook in a gust of wind, and Mars didn’t look up. She sat cross-legged on top of her sleeping bag, hunched forward with the laptop balanced on a folded camp pillow, the headlamp strapped so tight across her forehead it left a red line above her eyebrows. The light painted her face blue-white and threw a huge, hunched version of her shadow against the nylon wall behind her. Every time she moved, the shadow moved a half-second later, like something else was sitting in the tent with her.

The trail mix had fallen over at some point. Peanuts and chocolate chips scattered across the sleeping bag near her knee, and she’d left them there because picking them up would have meant taking her hands off the keyboard. A half-empty water bottle sat in the cup holder of the camp chair beside the tent door. The tent zipper was still closed. Outside, the forest had gone silent in the way that always made her bladder twitch, but she ignored it.

On the screen, the cursor blinked at the end of a sentence.

Marceline Beck didn’t run. She turned to face the thing in the dark, her breath fogging as she lifted her chin and said, “Are you going to kill me, or are you going to fuck me?”

Mars read it out loud, voice low, but not low enough to be a whisper.

“Are you going to kill me, or are you going to fuck me?” She paused. “That’s good. That’s very confident. Women will like that. Men will be threatened. Perfect.”

She rolled her shoulders, pulled the flannel tighter around herself, and set her fingers on the keys again. She needed a monster with teeth. Not just teeth. There had to be a sound, something physical, like claws scraping stone. She could describe that. She reached for the water bottle without looking, took a sip, and held it in her mouth while she imagined it. Then she typed.

The wolfman’s claws caught on the stone floor as he circled her, each scrape a promise. He was taller than the doorway, fur matted with rain, and his cock hung heavy and flushed between his thighs, already hard. Marceline let him smell the heat between her legs. She didn’t close her thighs, because she wasn’t stupid—she knew he’d just tear them apart. But this was the part she liked: making him wait.

“Making him wait,” Mars repeated, but her voice had gone thin. She squeezed her thighs together without thinking. The sleeping bag rustled under her. Her chest felt tight and hot, and not from the cold. She liked the part where the monster was patient. More than that, she liked the part where Marceline acted like she wasn’t afraid when she obviously was.

She kept typing.

“You want to run,” the wolfman said, his voice a growl that lived under her skin.

“I want you to catch me.”

And then she lifted her shirt over her head, baring her breasts to the cold air, and turned around. Her hands went to the waistband of her jeans. She pushed them down slowly, deliberately, until the curve of her ass caught the firelight. “But if you catch me,” she said, “you don’t get to be gentle.”

Mars stopped typing. Her face was hot. She could feel a damp, aching heat between her legs, and it had nothing to do with the hike. She let out a long breath through her nose. “Okay,” she whispered. “Okay, okay. That’s hot. That’s really hot.”

She pulled her knees up and hugged them, resting her chin on the worn fabric of her hiking pants. The headlamp beam pointed at the tent door, making a circle of light on the zipper. Through the mesh window, the night looked thick and black. She couldn’t see the tree line, only the gray shape of branches moving against the sky. The wind made the pines hiss, and for a second she thought she heard something beyond the hiss, a low, wet sound like something large breathing through its mouth.

She clicked the headlamp off.

The darkness dropped over everything, immediate and total. She stayed still, listening to her own breathing, the click of her throat when she swallowed, the wind pressing against the tent like a hand. Her pulse was in her ears. Then she clicked the light back on.

“Ridiculous,” she said, but her hand was already on the bear spray. She didn’t let go.

She shifted onto her side, tucked the laptop against her bent knees, and once again faced the screen. Her thumb hovered over the trackpad. She scrolled up, reread the part about the claw dimpling Marceline’s ass, and made a small noise in her throat. Then she cracked her knuckles and began typing again.

He caught her at the edge of the clearing, one huge hand wrapping around her hip. His claws pressed into the soft flesh of her ass, not drawing blood, not yet. He lifted her like she weighed nothing and pinned her against a tree, bark scraping her spine. His cock nudged between her thighs, thick and hot, and she let out a sound that wasn’t fear.

“You’re so wet,” he growled against the back of her neck. “Did you think about this while you ran?”

“I thought about it while I walked.”

He laughed, and his teeth grazed her shoulder. “Then you’ll think about it while I fuck you.”

Mars read the last line out loud, her voice low and breathy.

“Then you’ll think about it while I fuck you.” She liked that. It was degrading, but in a monster way. It didn’t count as degrading if the person saying it also had claws and a knot. That was just biology. She wondered if that made sense to anyone else, then decided it didn’t matter because she wasn’t going to explain it.

She typed another sentence.

He pushed inside her in one slow, brutal thrust, and Marceline arched her back, gasping against the bark. The stretch was too much. It was never enough. His claws dug into the tree above her head as he found a rhythm, and each stroke made the clearing go soft and red at the edges. She came with a sob, cunt clenching around him, and still he didn’t stop.

Mars pressed her thighs together harder. Her hips made a tiny, involuntary roll against the sleeping bag. The seam of her leggings rode against her clit, and she let out a sharp exhale through her teeth. She didn’t touch herself. That wasn’t the point. The point was to write it well enough that someone else would touch themselves.

She wiped her palm on her thigh. “Okay. Okay, that’s enough of that.”

But she didn’t delete it. She scrolled back up and read the whole scene from the beginning, skipping only the typos. When she got to the line about Marceline pushing her jeans down slow, she bit her thumbnail. The nail was already raw, and she tasted metal. She pulled her hand away and wiped it on the sleeping bag.

Outside, something moved.

Not close. Not far. A single clean snap, like a green stick breaking under weight. It came from the left, beyond the usual wind noise, too loud to be a squirrel and too sharp to be the tent settling.

Mars went still.

Her breath caught and held. The headlamp beam flickered once as she straightened too fast. The laptop slid off her knees and hit the tent floor with a soft thump, the screen going black as the lid bounced. The tent suddenly felt very small.

Another snap. Closer.

Mars’s heart slammed into the base of her throat. She could feel it in her ears, in her fingers, in the soft skin under her jaw. The bear spray was in her hand. She squeezed the canister until the plastic crimp dug into her palm.

Then the silence came back, heavy and waiting.

“Okay,” she whispered. “Okay okay okay okay.”

She was already moving. She shoved the laptop aside and scrambled to her knees. The sleeping bag twisted around her ankle, and she kicked it off. The headlamp beam swung wildly across the tent walls, casting her shadow at impossible angles. The trail mix scattered further. Her knee came down on a peanut and she didn’t feel it.

She had to get out. Inside the tent, she couldn’t see, couldn’t move, couldn’t do anything except sit in a nylon bag like a granola bar in a wrapper. Outside was worse, but outside had room to run.

Her fingers found the tent door zipper. She yanked.

The zipper caught.

It snagged on a fold of fabric, teeth locking at the midpoint. She yanked again, harder. The whole tent wall shuddered. The zipper didn’t move.

“You absolute—” She pulled with both hands. The zipper pull came off in her fingers.

Mars stared at it. The tiny metal tab sat in her palm, warm from her skin, useless. “No. No no no no. Are you joking?” She tried to thread the pull back onto the track, but her hands were shaking too much. The metal kept slipping. The zipper teeth were still closed, sealed, a line of tight little jaws.

Outside, another snap. Closer now, to the right. Or maybe the same direction. Her head whipped toward the sound, but the tent wall was only an orange-gray glow under the headlamp. Her shadow lunged across the fabric like something trying to get in.

“Fuck this.” She dropped the zipper pull. She grabbed the bottom of the tent door and tried to shove her fingers through the gap, but the zipper held. She braced her foot against the tent pole and pulled the fabric hard. The whole tent lurched. There was a high, sharp ripping sound. The door peeled open a few inches, then enough for her to get both hands through.

She pushed the flap aside and scrambled out.

She hit the ground on her knees, one elbow, and then pushed up. Pine needles and cold dirt ground into her palms. The headlamp beam cut through the dark, jumping from trunk to trunk. The air outside was cold and wet, sharp with pine and rotting leaves. Her breath came out in jagged white clouds. She swung the beam left, right, left again. The forest threw back only trees and shadow.

The tent sagged behind her, door gaping, torn fabric flapping in the wind. The laptop lay inside, abandoned, the fan still whirring faintly. Her bear spray was clutched in one hand, finger on the trigger. Her pants were wet at the knees with dew, maybe not just dew. She could still feel the damp heat between her legs, and it made her feel like an idiot.

Another snap, from the left again, but this time she caught the movement. Not a footstep. A branch, bending. A small pine at the edge of the beam dipped and swayed. Something was in there, too low to be a person, too heavy to be a squirrel.

Mars took one step toward the sound, then another. Her legs shook. The beam wavered. She could hear herself whispering, “This is so stupid, this is so stupid.” But she didn’t turn around.

The pine shivered once and went still.

Mars raised the bear spray a little higher. Her voice came out cracked and too loud.

“Hello? If you’re a deer, I’m going to be really embarrassed.”

The trail had gone quiet an hour ago, the kind of quiet that made Mars check over her shoulder twice and then pretend she hadn’t. Her boots crunched over pine needles and loose shale, the sound too loud, too human. She adjusted the strap of her daypack, thumb brushing the canister of bear spray clipped to the front. Still there. It had been there four minutes ago. It would be there four minutes from now, but her thumb kept finding it anyway.

The cave wasn’t on the trail map. That was the first problem.

Mars stopped a good twenty feet from the mouth, already shaking her head. It was the wrong kind of dark. Not the soft, friendly dark of a tent at midnight, but a wet, waiting dark that didn’t end. The opening was maybe eight feet high, a ragged split in the hillside, edges softened by moss and dead leaves. A cold draft pushed out of it and hit her face, carrying a smell she didn’t want to identify. Wet stone. Old rot. Something faintly sweet.

“Nope,” she said aloud. Her voice came out small and fast. “No, thank you. Absolutely not.”

She turned to go. Took one step back up the trail. Her boots scuffed. She could already picture herself in the parking lot, still alive, eating gas-station trail mix, posting a TikTok about how she almost found a cave. That would be fine. That would be content.

Then she heard it.

A sound from inside the cave. Not a rock falling. Not wind. High and thin, like a person trying to say something with their mouth closed. Or a child. Or an animal. It came again—a short, broken whimper—and the hair on her arms stood up beneath her flannel.

Mars froze. Her fingers found the whistle lanyard around her neck and squeezed.

“That’s a fox,” she whispered. “That is a fox with a throat problem. That is not a person.”

The third time was less whimper and more a dragged, wet exhale, and her body made the decision before her brain caught up. She was already walking toward the cave, knees weak, heart slamming against her ribs. Her phone was in her hand. She didn’t remember pulling it out.

“If someone is in there,” she said to no one, “and I leave, I’m a monster. A regular human monster, which is worse.”

She stopped at the cave mouth, close enough to feel the cold pour over her boots. The daylight behind her felt very far away. She unlocked her phone, thumb hovering over the record button. Her TikTok audience would not believe this. She could already hear the comments: girl run, that’s a demon, Mars you better not go in there. She opened the camera app and hit record, flipping it to face herself.

“Okay, so,” she said, too high, “I found a cave. Not on the map. And I heard something that could—could—be a person. So I’m just going to do a quick, very safe, extremely brief check.” She paused. “If I die, delete my search history.”

She stopped recording. It was a joke, but her hands were shaking badly enough that the video would look like an earthquake. She stuffed the phone into her back pocket, pulled the bear spray free, and clicked off the safety. Then she dug out her flashlight. The heavy old one, not the little keychain light she kept meaning to replace. She clicked it on.

The beam cut ten feet into the cave and died against a wall. Stone, slick with moisture. The floor angled down. The cold had a weight to it, pressing against her cheeks. She stepped inside.

“Hello?” Her voice bounced back at her, small and wrong. Hello, hello, hello. No answer. The quiet felt bigger in here, like the cave was holding its breath.

She moved forward, one hand on the wall, one hand holding the flashlight out like a shield. The ground was uneven—loose rocks, old leaves blown in from the mouth. She nearly turned her ankle and caught herself with a sharp gasp.

“This is so stupid,” she whispered. “This is exactly how the first five minutes of every horror movie goes. Brown-haired library assistant enters unknown cave. She dies. The cryptid guy from Reddit makes a fourteen-part documentary about her bad decisions.”

A few steps deeper, the smell got worse. Wet fur, she thought, and then immediately wished she hadn’t. Her flashlight caught something on the floor—a scattered pile of small bones, most of them cracked and old. A bird, maybe. Or a rabbit. The beam trembled.

“If that’s a warning,” she said, “it is a very dramatic one. Could just be an owl. Owls eat things. Owls are normal.”

She moved past the bones, because she was already inside and the sound hadn’t repeated. The cave curved slightly to the left. The walls narrowed. The ceiling dipped low enough that she had to bend her head. Her breathing echoed, too loud. She couldn’t hear anything over it, so she stopped and held her breath.

Silence.

Then, from deeper in, a soft scrape. Not rocks settling. Something slow, dragging. Like someone shifting their weight.

Mars’s grip on the bear spray tightened. Her other hand went to the whistle lanyard. She could blow it. The rangers knew her. They would come. They would find her body, probably, but they would come.

“Hello?” she called again, voice cracking on the second syllable. “If you’re hurt, I have a first aid kit. I also have bear spray, and I don’t know if that’s relevant, but it’s here.”

No answer. The scrape didn’t come again. Her flashlight flickered once, then held steady. She slapped it gently against her thigh, a habit she’d developed with the old thing.

“I’m going to be so mad,” she told the cave, “if this is just a raccoon. I’m going to be so mad and so relieved. Mostly relieved. But also mad.”

She took another step. The floor sloped more sharply. Her boot slid an inch, and she grabbed the wall to steady herself. The stone was cold and wet, and something came off on her hand—thin and fibrous, like old moss. She wiped it on her pants without looking too closely.

The beam swept ahead and caught movement. Small, darting. She yelped and the light jumped. A fat cave cricket sat on the wall two feet away, antennae waving.

“Babygirl,” she breathed. “You scared the shit out of me.”

The cricket did not care. It crawled into a crack and disappeared. Mars watched it go, then let out a shaky laugh that sounded vaguely hysterical even to her.

“Okay. I’m done. There’s no person in here. It’s a cave. Caves make sounds. They’re basically the earth’s basement. That’s why everyone hates them.”

She turned to leave, already rehearsing the TikTok in her head. I survived a cave encounter, kind of. She would call it “evidence review.” Maybe she’d rank the vibes. The comments would say she was unhinged. She would agree.

But then she heard it again. Closer this time. A low, guttural sound that wasn’t a whimper and wasn’t a scrape. Almost like breathing. Almost like a word.

Mars went very still. Her body understood something her brain refused to. Her thumb found the safety on the bear spray and pressed it back on by accident. She couldn’t fix it. Her hands weren’t listening.

“That wasn’t human,” she whispered. “That was not a fox. That was not a raccoon. That was not a bird. That was the cave. The cave is breathing. Old caves do that. It’s a thing. I read about it.”

She did not remember reading about it.

The flashlight flickered again. She smacked it. It died, came back weak, died again. Mars shook it, and the beam stuttered back to life just in time to catch the far wall. There was another opening there, low and narrow, a deeper dark beyond the dark. The sound came from that direction. She was sure of it now.

Slow, wet, and patient. Like something waiting for her to make up her mind.

Mars took a step back. Then another. Her boot hit a loose stone and sent it clattering down the slope, loud as a gunshot. She flinched, then fixed her eyes on the narrow opening, certain that whatever was down there would come pouring out.

Nothing did.

“Okay,” she said, too loud, “I’m leaving now. Sorry to bother you. Enjoy your cave. Great cave. Five stars. No notes.”