Dean sighed. "You asked for it. Pull the blinds down." The doctor did so, while Dean pulled supplies out. Silver, salt, holy water. After digging through the cabinet under the sink, he found a sodium borate cleaner. But the last was just a standby defense. The doctor gave him a perplexed look. Dean gazed steadily back.

"You see, I hunt things. Things that would scare the piss out of any normal person. I usually try to avoid admitting this, too. Doesn't go over too well. Dr. Harvey? You're right; he's not Dr. Harvey anymore. He's a freaky-ass, flesh-eating monster that wants me and my brother dead. That's the short story, anyway."

Dean poured salt and holy water into a plastic cup on Sam's bed table. "These are the tools that tell me whether you're a regular human, or some creepy critter out to get me. Drink up."

"Seriously?" The doctor wrinkled his nose.

"Well, I could throw it in your face, it'd tell me the same thing. But I kinda like to stay on the good side of people who can help me. Do it."

He did. No reaction, except pulling a slight face.

"Alright, that's one hurdle clear. Take this, by the way. It'll keep me from having to do that over." Dean handed him an anti-possession talisman. "Next is a little less fun. You gotta nick your arm with this." He held out the silver knife.

"This is all very funny. If you're brother weren't legitimately in ICU, I would demand to know where the camera was," the doctor laughed nervously. "What is all this for?"

"The full answer? Rules out demon possession, shapeshifter, werewolf, and a few other nasties that lurk in your nightmares." The doctor barked out a laugh, but Dean's expression didn't flinch. They stared each other down in the dark silence.

"Okay, fine." The doctor rolled up a sleeve, and, biting his lip, dug the point of the knife into his flesh.

"Okey dokey," Dean said, almost cheerfully. "And to boot, you're not bleeding black ooze. That's one of the telltale signs of a leviathan."

"A what?" the doctor spouted indignantly.

"What you last saw as Dr. Harvey."

Dean was grateful to find nothing. Utter, blessed nothing. Perhaps he could catch a break for once. He let the poor man clean up at the sink while he put everything away. "You're officially supernaturally clean. And that's a relief, because I need somebody in this craphole that I can trust to get Sam better. What's your name, anyway?"

The doctor chuckled, a sound somewhere between disbelief and slap-happy. "Carter. Dr. Jacob Carter. And what do I do, now that I've passed your little tests? Wrangle up a million bucks of hospital funds?"

"You're the only one in or out of this room. Even I'm not budging. Make sure of that. Leviathan Harvey can jump to anyone else. I'm not taking the chance that he waltzes in here and offs Sam."

"And what if he takes me over?"

"Knowing he's out there is our advantage. You said you noticed his arms were disfigured, when they hadn't been before—this guy, before he became Harvey, had the same problem. Apparently it's the one thing he can't shake when he changes form. That's our first sign."

Carter took a shuddering breath. "You deal with this stuff for a living?"

"Every damn day," Dean assured him.

"How'd he hurt his arms?"

"You don't want to know, dude."

Carter, now that Dean was letting him do his job, checked Sam over and noted the data on his chart. "I might as well know the whole story, if I'm dodging him for you."

"Have it your way." Dean sat on the edge of Sam's bed, fixing Carter with pointed stare. "He pissed his boss off, and as punishment, had to eat his own body." It would be a lie to say he didn't get some satisfaction from watching Carter turn green. "But unfortunately the boss got, um, sidetracked, and our friend managed to slip away."

Now Carter looked like the one who couldn't breathe. "Shouldn't he…shouldn't he be missing parts?"

"Another new development, one he admitted himself. As long as he's alive, he can go through the slow, painful process of regenerating. Fun, isn't it?"

"And how do you plan on killing it?"

"That's the best part—we haven't found anything that works yet." Dean's sarcastic smile was glued to his face. Yup, time to get some form of sleep. "Anything containing sodium borate will slow them down, but won't kill. Our working theory is that combining that with decapitation might be enough. So far he's the only one who's popped back up, and we didn't get to try it on him."

Carter stumbled back until he hit the rolling table, and leaned carefully on it. "Can't say you didn't warn me, I guess."

"End of the story is, he's after us. Specifically us. Once we're able to leave, he should get out of your hair. You can go back to saving lives without having to guard your own."

"One last question—if he's bent on killing you two, why do this? Why not attack you with a scalpel and be done with it?"

"I have no idea…"

It was late. They were both exhausted. Dean was losing his voice form talking. It went unspoken that Sam was alright for now and Carter knew enough to get on with. He left. Dean locked the door before allowing himself to flop into the reclining chair.

"It's gonna be a long few nights, Sammy."