Crimson Temptation

This is a fic about Marceline and Finn (as friends only). There is a serious lack of non-pairing fanfics for adventure time and that bothers me because although romance is important in the show, there are other important elements too, like adventure and friendship.

This is a very short multi-chapter fic that popped into my head and it hasn't been beta-ed yet, so I apologize for any grammatical mistakes. If anyone is up for being beta for this fic I would be grateful.

Also, I want everyone to be aware there is a lot of violence, gore and blood in this fic so I just wanted to warn you if you are sensitive to that.

Disclaimer: I do not own Adventure Time or the characters in this fic and I do not make any money by posting this fic. If I did I would just write all day every day.

Chapter 1: Unexpected Enemy

"Yeah man, this is awesome!" Finn laughed as brandished his sword before the monster, the moonlit sky illuminating his fighting stance.

A voice cackled behind him. "Yeah, this is more fun than I thought. Sometimes I forget how hard core a weenie like you can be. Who knew you would be up for taking down a Windigo?"

The human laughed again as he looked up at his vampire companion. "Killing evil things is what I'm all about!"

"Yeah well, that things not dead yet," Marceline pointed out as it snarled at the two of them, blood trickling from the top of its wounded head down its gaunt cheeks and dripping on the ground beneath its snarling fangs. The monster's bones seemed to protruded from its body and only a layer of thin dark skin stretched to cover them. The creature was three times as tall as Marceline and it reeked of death. At one point on time Marceline thought of taming one as a pet, but they were so damn hard to beat even for a vampire, so she never though it worth her effort.

However, Finns eye's seemed to brighten at the opportunity to fight one. Besides, for something that would have given her trouble, Finn seemed to be doing just fine on his own. Marceline was aiding Finn in his fight, but she couldn't help but get caught up in watching the action. It was unbelievable how something so small and human could hold his ground against something so large and supernatural.

Finn was quick, quicker than she remembered, and he was strong and didn't hold an ounce of enthusiasm back. His sword- his family sword- allowed him to deal blows that were actually causing mortal harm to the beast. How a dog family managed to get a sword imbued with demon blood she would never know.

She had always known Finn to be strong and reckless, and sometimes his bravery overwhelmed his common sense, but it wasn't until this fight that she realized how much potential he had. He was only thirteen years old and fun for him was taking down a cursed monster. Marceline had never once been remotely interested in seeing what mortals would grow up to become, but she couldn't help but wonder about Finn.

Finn assaulted the beast, using his sword to block the attacks of the Windigo's sharp claws as he ran underneath the monster. He jumped upward, stabbing the monster in the chest, and the Windigo let out an ear piercing howl. Before Finn could get his sword unstuck, the beast struck him with his paw, sending the human flying into a tree.

Marceline flinched at the loud crack Finn's body made against the tree, and she swooped down to float in-between the monster and the injured human. However, the monster seemed too preoccupied with tearing at the sword lodged in its chest to go after the boy again. Before Marceline could check on her friend, Finn was already getting to his feet, his hand clutched over his upper left arm, a grimace on his face.

Marceline could smell the blood even from where she was and she knew the wound was bad, possibly dangerous if he didn't get it bandaged soon.

To her surprise, Finn ran past her, heading straight for the beast. He was injured, he had no weapon or plan, but from the look on his face Marceline knew he was determined to finish the fight.

With the speed and experience of mortals twice his age, Finn dodged through the Windigo's legs and grabbed hold of his sword in his good hand. Finn yanked it out with ease, and sliced the beast's right leg in one fluid motion. The Windigo stumbled to the ground, nearly crushing the human. Finn took the opportunity and jumped on the monsters back, using both hands to pull himself up and seemingly managing to ignore the gash on his arm. The beast tried to claw him off, but Marceline understood Finn's plan and she knew the fight was already over.

Finn made it to the beast's snarling head, wrapped his legs around its neck, and plunged his sword through the top of the beast's skull.

There was an almost inconceivable second where the beast froze in confusion, and then it dropped like a stone. Finn rolled off its back onto the cool ground. He lay there breathing heavily.

Marceline couldn't move; that fight had been… intense.

As though he hadn't nearly just lost his life, or maybe because he almost did, Finn began to laugh.

It was an innocent, light hearted laugh, full of relief and joy.

"That was awesome!" he cried out, lifting both hands into the air, only to clutch his left arm to his chest a second later. "…Ouch."

Marceline chuckled to herself, placing a strand of her hair behind her ears. The kid was full of surprises.

Finn sat up to inspect the gash on his arm which had been caused by the beast's claw. It was bleeding profusely and his whole left arm was now drenched in blood. The cut was almost to the bone and Marceline wondered if Finn would soon pass out now that the adrenaline would be leaving his system.

Almost nonchalantly, Finn removed his backpack and began searching for something; medical supplies most likely.

Marceline floated closer to get a better look, but not too close. The scent of Finn's blood was making her dizzy and she didn't trust herself around that much blood. She had never tasted human blood before, but it was the most coveted of all blood and the rarest. Hundreds of years ago vampire clans would kill over who would possess the last of the humans, but now the vampires' favorite pray was gone. All except one.

It was too bad Finn was her friend because she could see why vampires risked their unlife for-

No. Stop it. Don't think like that.

"Hey Marcie, you okay?" Finn called over to her.

Marceline managed to force out a laugh. "Shouldn't I be asking you that?"

Finn shook his head, a large smile on his face. "Nah, I'm fine. Hmm, I can't seem to find the bandages though…"

Marceline could feel her stomach turned in unease.

"I must have forgotten to pack more after last time. We are close to your house; do you have any bandages that I could borrow?"

Yes, invite yourself over to a vampire's house when you're bleeding to death, Finn. That's safe.

Why doesn't he realize-? But she knew her answer.

Because he trusts you.

"You sure you can even make it to my house? In my experience you mortals need your blood inside your bodies to function."

Finn nodded. "Yeah…" His nose wrinkled like he was going to do something unpleasant.

Finn removed his hat from his head to reveal a mess of short golden-blond hair. Marceline almost fell out of the air. He looked so… human without that hat. Was that why he kept it on? Why did it feel so monumental that he would take it off? Maybe Finn was a little more desperate about the blood loss then he let on.

Finn frowned thoughtfully at the hat before he reluctantly tied tightly over his gash, flinching slightly. Finn may not be well educated, but he seemed to know enough about medical care to keep himself alive.

"Huh," Marceline murmured.

"W-what?" Finn asked nervously, staring up at her with wide eyes, his cheeks darkening slightly. He was obviously more self-conscious without his hat on his head Marceline noted in amusement.

"Nothing… let's get you to my house."

He would lose too much blood if Marceline made him walk back to his Treefort, and her lair was only ten minutes from where they were.

Finn stood up and placed his sword in his backpack's strap.

Marceline's throat burned as the overwhelming scent of his blood grew stronger. She swallowed reflexively. This was going to be difficult. Maybe Finn shouldn't be putting his sword away. He may need it again, but for an entirely different type of enemy.

There you go, chapter one done. I hope you enjoyed it, and if you haven't figured it out by now this fic is about the more vampire side of Marceline, and even though she can drink shades of red, the more primal side of her wants more than just the food coloring. XD

The chapters will get longer as we go, but for now I hope you have enjoyed yourself. And don't worry, I will update soon! Please don't forget to leave a review and let me know what you think. I appreciate reviews very very much and I would love to hear from the lovely AT fandom!