Disclaimer: I don't own Prototype or Adventure Time

Anyway, this is an idea I've had bouncing around in my brain. I'm a bit worried people won't like it, which is why it took so long for me to start on, then i just said "Those people can just deal with it" and started writing. Let me know what you think.

Of Men and Monsters

There are very few monsters who warrant the fear we have of them.

- Andre Gilde

Chapter 1

Finn swung his new sword through the air a few times, testing its balance. Though neither too heavy nor too light, the balance just felt wrong. Ever since freeing Jake from Kee-Oth's Pit of Despair, Finn hadn't been able to find a sword that felt as good as his demon-blood sword had been. Finn sighed and put the sword back into its scabbard, continuing down the road.

"Hey Finn," Jake asked him quietly, "what's wrong? You ain't still bummed about losing your sword, ain't ya?"

"No. I'm just trying to get used to this new sword is all."

Finn's new sword was of simple design. It had a shiny, bronze pommel, and a steel blade. It also had small emerald, about the size of a large marble, embedded in the cross-guard. It wasn't as long as the demon-blood sword, but the blade was heavier so it weighed about the same. Finn had found it in the pile of loot in their basement. It had been dull, and a bit rusty when he found it, but a good sharpening and polishing had made it look good as new.

"Hey, don't worry man, you'll get used to it. You'll be fighting evil like usual in no time." Jake told him

"Yeah, your right. So, how far are we from this vault anyways?"

They were out on a mission. PB had given them a map with directions to an old pre-war vault out in the badlands. She said something about technological wonders and lost secrets that would end up being beneficial to the kingdom. Of course, they would probably have gone with or without being told that.

"We're about a mile away, according to the map." Jake reported.

"Awww, YEAH!" Finn shouted, his usual vigor back. He raced ahead of Jake, who had to stretch to catch up, and soon the two were running down the path, ready for whatever the vault contained.

Or so they thought.

A dark shape sat in an even darker room. Though it was patient, this being had begun to think that it would never escape, never again be able to feed. The exit mechanism had broken long ago, and trying to break down the door would bury it. So here it sat, starving, awaiting the opening of the vault, or the end of the world.

The door of the vault creaked open, its ancient hinges groaning with one-thousand years of rust. The monster of the vault opened its eyes, and smiled.

Finn peered into the darkness. He looked at Jake and said, "Whoa, how old do you think this place is?" Jake shrugged "It looks at least as old as the Lich's lair." Finn shivered, remembering the old underground ruin where he'd first fought the Lich. "What do you think we'll find in here?" Finn asked. "I don't, know," Jake replied "but we won't find out by standing around." Jake then walked into the dark vault, which gaped from the side of the mountain it'd been built into like the maw of a prehistoric beast. Finn followed him, lighting a torch as he walked.

They made their way through an abandoned hallway. The walls were lined with dusty electric lights, that looked as if they hadn't been lit in years. They walked through the darkness, descending several sets of stairs. They came to a sign, long faded, but still legible.

"What does it say?" Finn asked. Jake read it "It looks like, directions to the power switch." He replied "Well, that's handy."

They followed the signs and eventually reached an old machine. It was large, and looked mostly unused. There were no instructions, but the large lever that had the word "LIGHTS" written next to it gave a distinct clue about the machine's function. Finn approached the lever.

"you don't seriously think that after all this time that machine would still-" But the words died on his lips as Finn pulled the lever and the machine sputtered and hummed to life. The light flickered on and from somewhere in the distance, music started playing. Finn looked at Jake and nodded. The two silently made their way up the stairs again and towards the music.

Finally, they reached a large doorway. From beyond the music played, the soft, sad sound of a violin. Together they both rushed into the room, screaming battle cries, Finn with his sword drawn, Jake having grown to three times his normal size. What they saw amazed them.

Beyond the door, several halls lead further into the vault. The ceiling lead up, unbelievably high, with even more hallways on each floor. "What is this place" Jake asked. "This entire mountain looks hollow," Finn stated with disbelief. From the ceiling of this massive foyer hung the largest chandelier either one had ever seen. It was large enough to build a house on, and shone like a crystal sun.

The music that they'd followed came from an old record player, sitting at the side of the room. In the center of the room, directly underneath the chandelier, sat a man. He was covered in dust, and looked as if he hadn't moved in centuries. His eyes were closed, and he didn't even seem to breathe.

"Is that what I think it is?" Jake exclaimed.

They both approached the man.

"It sure looks like a human." Finn said, "a REAL human too, not a fish-head mutant." "Is he dead or something?" Jake asked. "It looks like it," Finn stated "I don't think this guy has moved in years."

Just then the record player stopped playing. Finn and Jake looked away from the man for a minute. When they looked back, he was standing.

"AAAHHH!" They screamed simultaneously. They fell backwards and landed flat on their backs. The man opened his eyes. He stared at the open door, inhaled, and then, he spoke.

"To answer your question, no I am not dead, nor have I moved in years."

Finn stood up and looked at the now moving man. "Who are you?" he asked "and what are you doing in this vault." The man eyed him and said "Well, I guess telling you couldn't hurt. My name is Alex, Alex Mercer. The reason I am in this vault is because, well, I had nowhere else to go. I had wandered for a few years, found this place and locked myself in."

The man named Alex was now walking through the halls of the vault, making his way towards the exit. Finn was following him, listening. Jake trailed a few feet behind the two, curious, but also suspicious. How could a human have survived so long down here alone?

"Inside, I found several people, and collections of music, books, and various other things of the like. The others quickly died out, and soon only I remained." Alex continued. "So, if you were alive this whole time, why were the lights off, and why did you look so, dead?" Finn asked him.

"The lights were off because after going through all the books, music, movies, and other junk, I got bored. So I turned off the lights, and slept, and now you two have opened the door for me, so now I can leave."

The three walked on in silence, before Jake worked up the nerve to ask, "How long have you been in this vault anyway?" Alex looked back at him, his face unreadable. "Almost a thousand years, and after all that time, I am starving."

Finally they neared the exit. Jake stopped and tapped Finn on the shoulder. He whispered in Finn's ear "Watch out Finn, this guy is giving me the creeps, keep your guard up for if he tries something."

"What are you whispering about?" Alex called to them. Jake laughed nervously "Oh just telling Finn here how delighted the princess would be to see you, when we take you to meet her." Alex was quiet for a moment, then stared at them with a sad gaze.

"I'm sorry, you seem like good people, even if one of you is a talking animal, but you aren't leaving."

It took them about a second to figure out what Alex meant. Finn drew his new sword and got into a fighting stance, as Jake grew to about twice normal size.

Alex continued to stare at them.

"Again, I'm sorry. It's just that I haven't eaten in almost a millennium, and you can't expect me to control myself when fresh meat just wanders up to me can you?"

Well, there it is, chapter one. This is probably going to be another long fic, so let me know what you think. The more feedback I get, the more my writhing can improve. TommyGun15 out.