Author's Note: Ok, this is obviously AU since it's crossover, but it's a little more than that. I am actually only in Season 3 of Supernatural, so I am nowhere near to the part where Sam is in the Asylum for Lucifer speaking to him. However, I saw this awesome gifset on tumblr about what would happen if Buffy and Sam met while they were both locked away…and this is what happened. Let me know what you think.

Disclaimer: I do not own any of the recognizable characters.

Chapter 1: New Roommate

"Winchester!"

Sam looked up as he heard the orderly, Mark call his name.

"You got a new roommate." Mark announced as he practically dragged a short girl with long blond hair all around her face in by the arm.

"Little odd to room me with a chick isn't it?" Sam asked as he watched his new roommate walk run instantly to the corner where she balled up as if trying to disappear into the wall.

"Yea, well, we got a little bit of an over-crowding issue as of late. So we decided that since you guys have pretty much the same case we could just put you two together and not have to worry about you hurting each other." Mark explained.

He didn't mind Sam. He didn't really think he belonged in here. But the kid insisted that he hunted demons and that he had conversations with Lucifer himself. You'd never guess it if you were having a normal conversation with the guy, but if the conversation turned to anything of a supernatural nature, out came the bird from the cuckoo's nest. In all honesty, if the kid took some prescription schizophrenia medication he could probably be a fully functioning member of society. Heck, maybe he could even go back to Stanford Law like he had mentioned.

"What do you mean we have the same case?" Sam asked instantly curious.

"She thinks she kills demons, too. No talk of talking to the big man yet. Guess that makes you special, Sammie." Mark winked at him.

"Don't call me 'Sammie'," Sam snapped, forgetting momentarily about the fact that Mark just told him that this girl was a hunter.

"Hey, my bad," Mark stepped back with his hands up in the air in surrender. He didn't see Sam snap that often. Come to think of it, he'd never seen Sam snap out of anger.

"Sorry, it's just," Sam hesitated and then got a pained look in his eye. "My brother called me 'Sammie'."

"Got it," Mark nodded. "Alright, well I'm gonna go. You guys get to know each other. My shift is over, see you tomorrow, Sam."

"See ya, Mark," Sam nodded as the orderly left.

He studied the girl. If Lucifer wasn't constantly bugging her, what had made her snap? Maybe she was recently possessed and she had trouble coping with what the demon had done with her body. Sam had been there, but he had gotten through it with Dean's help. This girl was practically catatonic. Mark had mentioned that she was a hunter. Maybe something got a hold of her and made her like this on purpose.

Oh well, Sammie, only one way to find out.

"Hey," Sam said gently.

She made an almost imperceptible move to acknowledge that she'd heard him.

"My name's Sam," he tried again, this time moving closer to her and crouching in front of her to get eye level. "I guess we're gonna be roomies for awhile."

Suddenly she got a scared look on her face and started to back even further into the corner. "Roommate. Demon. Roommate's a demon," she muttered to herself. "Roommate from Hell."

"No, no, no," Sam rushed to assure her. "I'm not a demon, I'm human. In fact, I'm a hunter, like you."

"Hunter?" She looked up at him strangely.

"Yeah," he nodded, glad she had calmed down. "Me and my brother, Dean, we're demon hunters."

"No," she shook her head. "Demons not real." The shaking of her head got so intense that Sam thought that she was about to have a panic attack.

"Is that what they told you when you got here? Demons aren't real and that you're just delusional?" Sam asked.

She calmed back down and simply nodded at him, tilting her head as if interested to see what else he had to say.

"Can I tell you a secret?" Sam whispered conspiratorially to her.

She nodded again. "I'm good at secrets."

"The doctors here? They don't know the truth. The demons are real. You and I? We know better, and we hunt them to keep these people safe. Safe from what lives in the dark. What goes bump in the night." Sam told her as if telling a child about super heroes. Whatever demon had gotten a hold of this girl had really done a number on her head. He wished he could pray to Castiel as soon as he got out of here to come and heal her so she could get back to her life. This was no way for any respectable hunter to waste away.

"The demons are real?" She asked wide-eyed. "The vampires are real?"

Sam nodded, excited he was finally getting through to her. "Yeah. Vampires, is that what you specialize in? What you hunt the most?" He held his breath for a second; he really didn't need another Gordon on his hands right now.

Again she nodded. "Slay vampires."

Sam's brow furrowed as he focused on what she said. 'Slay vampires'. Not hunt, or waste, or kill, but slay. Why did that sound so familiar to him? It was itching in the back of his head that he had read about something like that before.

"You never told me your name," Sam said, pushing his previous thoughts to the side.

"Buffy. Buffy Summers." She almost whispered, as if she was confused by her own name.

That name sounded familiar, too. Where the heck had he heard that name? Then it hit him.

Sam's new roommate, was the Slayer.