Disclaimer: I do not own Adventure Time. I just don't. I wish I did, 'cause it's awesome, but I don't.

I was looking at Gumlee pictures and happened upon Finn/Marshall Lee and I kind of liked it. So I browsed the few stories that there are of that pairing and decided to write my own. I hope you like it! :)

Chapter 1

Finn should have known it was a bad idea to go into PB's portal by the way it looked, all swirling with bright dots—magic things and Finn didn't go together. He was just bored; Jake was so busy lately with his kids and Lady, so sneaking around her lab seemed like fun. Jake would've stopped him from jumping in the magic portal. Maybe that was why he did it, because he missed their adventures. He saw the papers on Bubblegum's desk, and thought about reading them in case he was diving in to his death, but in the end he glanced at them and jumped on it.

And in the end, it was a mistake to do that. Now he was stuck in some weird other place, wandering a forest that looked familiar but totally wasn't, tired and hungry, and the worst thing was his head hurt because he fell out of a tree and hit it like a loser

Sidestepping a cliff that came out of nowhere, he put his hands in his pockets and grumbled. "Math, this sucks."

The creatures in the trees followed him while he sulked. Black birds and deer, and some weird looking other ones he didn't know the names of. But as he kept walking, hoping for some civilization and someone aside from animals, the sun began to set—that meant danger. He had his sword with him, and maybe other things in his pack, but in a place he didn't know anything about darkness meant less chance of survival.

He began to walk faster, looking for a place to sleep for the night. It was pure luck he happened upon a cave without anything in it.

Looking out of the entrance he watched the sun go down. Sunsets were pretty from his tree-house, lately he'd watched a lot of them and just had deep thoughts about his life that seemed to be put at a halt. Jake had a family now, and Finn's family was just BMO—don't get him wrong, he loved the little machine. He had just hoped for more. And on this mountain, overlooking the forest he'd spent hours wandering, the sun was so bright and the clouds so pink, Finn thought his sunsets didn't compare.

He sighed. He had enough of this depression that overtook him at random. He was in a different place and had to get his head together. "I need to make a fire before all the light is gone."

Firewood wasn't hard to get, and soon he had a small one going. He dug through his bag with hope that his marshmallows Jake gave him a few days ago were still in there, and they were. He ate them for dinner, but a few marshmallows wasn't enough and Finn knew he'd have to wait for dawn to find more food. Thankfully he ate some berries earlier or he might've passed out from exhaustion.

The sun was fully down and the smidgen of light was gone. Finn couldn't see anything aside from the few feet surrounding the fire.

Out of nowhere it started to rain. Hard. So much water was falling he couldn't see anything outside. "What the glob?"

When a breeze flew by, the fire began to flicker. Finn hissed and held his body tight, arms around his chest. He glared at the glowing flames. "Come on fire. Do your job."

"Sorry, dude. I just wanted out of the rain."

Finn screamed and fell backwards when suddenly a guy appeared out of nowhere, floating in front of him on the other side of the fire. "What the hell, dude! Don't scare someone like that!" He rubbed his head where he bumped the same spot as earlier, and sent evil-eyes at the intruder.

The man, a really pale looking one, who was actually kind of attractive wet with his shirt sticking to him, let out a laugh. "Ha! Scaring people is my life."

Finn brushed the dirt and rock pebbles of his body. "Jeez." Then he really looked at the stranger and gasped. He looks just like—but not—glob, where am I? What did those papers on PG's desk say? Alternate Reality? Then he has to be.

"Why are you looking at me like that?" the guy asked. He floated around the fire until his face was inches away from Finn's, who leaned away from him. "You know, you're a cutie." He smirked. "What's your name?"

Finn grumbled and blushed, facing away from the closeness of the intruder of his cave. "I'm not cute. And my name's Finn."

The stranger grabbed his cheek with a cold palm to turn his head back. Finn slapped it off; the coldness was too much when he was already freezing. The stranger was smiling though even after he shoved his hand away, and his red eyes gleamed. "Finn. I'm Marshall Lee, Vampire King."

Finn knew for sure when he said this he was in some opposite universe. Marceline was now a boy named Marshall Lee. So he must have someone named…well, he didn't know, but it was probably pretty close to his name. But Marshall didn't act like Marcy at all. If he did, then Finn wouldn't be in this cave anymore as she would've claimed it as hers, the damned possessive vampire.

Finn put on his best smiles just in case he had a chance of being thrown out in the pouring rain. He couldn't beat off a Vampire King with his flimsy sword, and said sword was far in the back where he couldn't get it, so he had to make sure he stayed in the safe cave. "It's nice to meet you, Marshall."

Marshall hummed and gave him a strange look, with narrowed eyes and a puckered lip. "Yeah… You look like someone I know…"

"D-do I?"

Marshall grinned. "Yeah, but not as cute." He leaned forward and rubbed Finn's cheek with his own, which was cold and wet with raindrops. "You smell good."

Finn froze. What. The. Glob. Marshall just moaned into his ear, and fucking nuzzled him. Nuzzled Finn. "Who do you think you are?" Finn shoved his hands against the cold, wet chest to move Marshall away. He stared into red eyes, eyes that seemed to smirk as much as that mouth. "Don't touch me."

Marshall grabbed Finn's wrists and brought his hands behind him to wrap around his slim waist. Finn's hands were forced to set against a wet lower back, and he could practically feel the skin beneath. The vampire leaned forward again to a still Finn, his hair sliding across the younger's cheek, and said with complete cheekiness, "Stop me, Finny."

Hearing that challenge, Finn snapped out of his daze and dove at him. How dare this complete stranger from a different land seduce him? Touch him like that? It was…pervy and weird.

With all his strength, which wasn't much, Finn pinned the vampire by his shoulders to the dirt-dusted rock floor. But just as he was about to punch that face that sent shivers down his spine for reasons he didn't understand, Finn was grabbed at his waist and thrown over on his back and pinned down himself, and it hurt. His vision blurred and he held his breath when he feared the taste of vomit would come up his throat. The weight of the vampire on his stomach wasn't helping, and the pounding in his head was getting worse. He closed his eyes with a groan.

"Shit, you okay?"

Finn leaned his head over and puked.

Marshall Lee flew up off him.

Finn began to cough and choke, so he got on his hands and knees and let out more, but it was mostly stomach acid after the first and it burned like lava. Throwing up sucked.

He nearly fell in his puddle of puke, feeling his legs and arms shake, when arms wrapped around his stomach and lifted him up to sit on his butt. He spit out some leftover vomit.

Marshall frowned at Finn. He knelt in the air in front of him. "You sick or something?"

Finn grabbed his head, squeezing his eyes shut as it throbbed again. "Don' know."

He felt gross. He looked out at the rain and began to crawl towards it, water sounded really good.

"Hey, where're you going?"

The vampire blocked him, feet planted on the floor in front of Finn's face. "Move." His voice sounded scratchy and awful. "I need water."

Marshall Lee huffed. He looked around the cave and then flew away. With him out of the way, Finn panted as he crawled again towards the rain, each little move causing his head and stomach to send him discomfort. Why was it so hard to crawl? Babies did it, why couldn't he?

Looking down at his trembling hands, Finn wanted to cry at how weak he was. In front of a stranger no less, trapped inside this cave. Life hated him right now.

"Here, take it."

Finn looked up at Marshall. He held out a rock that was dented so badly it looked like a bowl—what creature lived here before, he thought—and when Finn took it he saw the water inside. He downed it in one gulp, thankful the sour taste was gone. "Thanks."

"No problem."

Finding the nearest wall by the fire, Finn leaned against it and put his head on his knees. He began to tremble from the cold even with the heat of the fire.

The vampire sat beside him. "You got a big bloody spot in your hair."

"I know."

An arm wrapped around Finn's shoulder. It was unexpectedly warm, unlike Marshall's hands earlier. Finn couldn't help but lean into him. "You're colder than me, and I'm a fucking vampire." He let out a huffed laugh.

There were so many things wrong right now. It smelt like mold and barf inside the cave. Adding to that was the flickering, dying fire—Finn knew he should've gotten more wood—with the storm waging mere feet away. Plus there was his sudden sickness. But despite that, Finn pressed his face into Marshall's wet shirt, and in the stranger's embrace he felt better. He ignored the stench and didn't care about the blackness that would soon come when the fire spurted out and succumbed to his own darkness.

That's the first chapter! I've got more so I'll get the next part up when I can :) I feel like my Marshall Lee is not very Marshall Lee haha. Let me know and I'll try to make it better.