A/N: Here's a bridge-fic of sorts for my Physician series, which may be detouring from Dean for a while but it's definitely going to become relevant. There is actually nothing to do with hearts in this. Amazingly. And I'm sure many questions will be raised. But the final part of the series is coming up, and there's some important context here for when you find out what happens to Dean. I invite speculation.

Chinatown, Los Angeles
2009

The visitor didn't knock. Nor did he, apparently, enter through the doorway at all, yet there he is when Carter enters her kitchen, standing by the sink with cold eyes levelled intently at her.

She doesn't recognise him. Granted, she rarely remembers the demons who do show up here more than once, yet she has a feeling this one is new. They haven't met before.

He addresses her first, his voice a cold, unsettling drawl. "Dr Carter."

She crosses her arms across her chest and shoots back a glare equally cold. "It's by appointment only. Or at least people who do the courtesy of knocking first."

"Don't you worry. I'm not looking for an appointment." When he speaks, his voice is breathy, enunciation drawn-out and slow. It reminds her of a creeper phoning some sex line. "Just here for a little assistance with another matter."

Something about him perturbs her. Her fingernails dig into the bare skin of her left arm as goosebumps began to rise. "The door was locked."

"It was."

His footstep as he takes a single pace closer seems unnaturally loud. Carter holds her ground. "What do you want?"

"I'm looking for a demon named Ruby."

"You're out of luck. I may not be good with names, but I haven't treated a female in months. Look elsewhere."

A strange noise sounds in the back of his throat, which may have been an expression of disappointment if it hadn't somehow sounded sarcastic.

"A pity," he remarks, again stepping closer. "Although perhaps if I…wait around, she may show up."

Carter gives him her most cutting fake smile. "If she does, I'll let her know you called."

"Don't you need to know who to tell her was looking?"

"I already do."

That prompts a raised eyebrow and a rather smug smirk. "Do tell."

"Sure, Alastair. I know who you are."

That seems to please him. "Even on earth, my reputation precedes me."

"Yeah. You get demons under the knife, they start talking. As I'm sure you know. Your name came up once or twice."

"Nothing good, I hope."

Now it's her turn to smirk. "I think they appreciate my skill with a scalpel a little more than yours."

A beat, and then he chuckles, low and menacing. "Oh, I'm sure they haven't yet seen the full extent of your skill."

That triggers just a flicker of uncertainty in Carter's defiant glare. Her breath draws sharper, a slight hitch before her eyes harden into steel again. Alastair notices. A smug look settles on his face as he saunters over to the kitchen counter, Carter watching in silence. Assessing. Judging. She still doesn't move as he reaches out to run his fingers over the handle of a knife in its stand.

"I hear alchemy is your forte," he remarks, eyes wandering over the other items on the counter top. There are various used syringes strewn across the marble, a sharps disposal, a chopping board with sigils carved into the wood, while by the sink sit a pestle and mortar and an array of beakers half-filled with various chemicals. His gaze seems drawn to the two large syringes not yet emptied, an inky black substance filling their chambers. "One of the few practicing alchemists left."

"You're not wrong." Her tone is cautious. He's still toying with the handle of the knife, but that look tells her he's curious about the contents of those syringes.

"Azoth?"

"Not quite." She wonders what it matters to him. "But it keeps me ticking over."

A calculating look passes over his face, then he changes tack. "You know, I really wish you could assist me with finding Ruby. But failing that, I'm sure the day will come when you will be of great assistance to me. Someone of your skill would be…invaluable."

The knife grates as he draws it just an inch from its holder, then slowly pushes it back in. His eyes lock onto hers. The threat is unmistakeable.

"You mean in Hell? Cos that's not gonna happen."

"Oh, but for an artist like you? It would be such a waste of talent…"

"Not if you paid me." It comes out as a snarl. "And they did. Pay me. A lot."

She isn't sure how much he already knows about her, or how he knows it, but it's a fight not to let her discomfort show as he leans in closer with a sneer. "Oh. I know."

A beat draws out as they stare each other down, and then Carter's own lips curl up to match his look of menace. "I've been dead fifty years. As I'm sure you know. But that stuff there," – her eyes flit to the syringes – "Is keeping me anchored to this Earth, and I have no plans to be leaving it any time soon."

"A pity." He deliberately grates the knife again. "It's just that with an Apocalypse on the horizon, you might want to rethink your position."

That only gets a dry laugh. She leans away from him, throwing her arms up in a gesture of mockery. "You know, I was on-the-ground intelligence during World War II. The Cold War. I saw a dozen apocalypses come and go. Nuclear Armageddon, they said. Each time. And yet here we still are. I'm not worried."

She can't be sure, but she thinks his eyebrows raise up higher, realising maybe he's failed to get what he wants. The knife blade grates again. She wonders if he's actually going to draw it, and then decides to beat him to it.

Surprise flickers briefly on his face as she reaches past him to snatch another knife from the stand, and then, to an even greater look of surprise, she turns the blade and sinks it into the flesh of her own upper arm. He watches in silence as she carves at the skin and then hacks away a chunk of tissue, all the while her gaze locked defiantly on his face. Blood trickles down. "You were planning to torture me? Don't waste your time. I can't feel a fucking thing."

Another beat. He looks at her, once again calculating, and then a slight smile tugs at his lips. He seems disconcertingly pleased. "You know, it usually takes me centuries to torture a human soul to the point at which it becomes a demon, but you? You've done worse to yourself in half the time. I'm impressed."

She glares. "Don't presume to think I did it to myself."

That only seems to cement his satisfaction. He chuckles and steps back from her. "Well, if Ruby does show up here, you be sure to let me know." He seems to be finished, turning and heading for the door.

As glad as she'll be to see him go, Carter isn't quite done. "Alastair." He pauses, looks back. "Don't flatter yourself. You may be some big shot torturer in Hell, but I promise you, I've seen humans capable of far worse."

That draws out another smile, a smug grin of barely-contained glee twisting on his face. "I know." His eyes flash black. "You look in the mirror each morning."

He steps out into the corridor and the door closes behind him.