Disclaimer: Don't own Supernatural or the characters. Except the OCs. Which no one wants anyway.

Notes: I could say the timeline in this is tricky, or be fairer and say it's just really self-indulgent. It's set pretty soon after The Rapture, but ignores the Vampire-Sam arc and is therefore bizarrely AU.

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The funny thing about it, when Dean looks back on it later – funny in the bang your head against the wall kind of way – is that there isn't even a reason for Castiel to be there. It's not a seal. It's not even a hunt, really. It's just Dean and Sam, good Samaritans at large, checking up on a rumour of a haunted barn in the middle of Nowhere, Oklahoma.

Turns out the barn is the local chapter of Demons Anonymous, and whoever sent them out on the goose chase was almost certainly in on it in on it, in a "ice = almost certainly cold" kind of way. And all just because some would-be big-shot wanted to have a chat with Sammy around a nice homey fire. Things get ugly real quick, but they get a hell of a lot uglier when the big-shot produces a pack of underlings. Which is when Castiel shows up out of nowhere to barrel into a couple of demons almost a foot taller than him. Unfortunately, it's also just about then that Sam gets thrown through a wooden pillar and ends up sprawled in a confused heap on the rough floor, while another bastard drops down out of the rafters – seriously, what the hell? – to tackle Dean to the floor and press a knife to his throat. From the way he's pressing the blade good and tight against the skin, it's apparent he's not going to be too bummed out if he nicks something vital.

Castiel turns towards him, giving a perfect opportunity to the demon behind him to nail him with the mallet it's swinging. It does, and Castiel goes down. He's picking himself up again almost instantly, of course, but it slows him down enough for the bastard with the knife to jerk Dean's head up, conveniently baring more of his throat. Castiel pauses, with the last two demons circling around to hold him down on his knees. The boss, as far as Dean can tell, steps out from the shadows, holding a cattle brand in one hand. The end, a convoluted circle, is red hot.

"Now, Sam and I need to have a little chat," he says to Castiel, who watches him flatly. "And while I'm happy to keep Dean here as a guarantee of his good conduct, I don't need any choirboys hanging around to go squealing to Daddy. So you're going to take off and leave your host behind to keep you from popping back in again, or my boy there will slit little Dean's throat."

The hand in his hair twists and grasps hard enough to bring tears to Dean's eyes as his head is yanked back even further. He knows from the pain at his throat that the knife's already drawn blood.

"You need him," says Castiel gruffly. "You won't kill him."

"He's an aid, not a necessity. And I'd get a hefty prize for sending him back downstairs. He's got plenty of friends waiting for him."

"He was raised once. He can be raised again."

"You guys wanna stop tossing be back and forth like a damn baseball?" Dean's quip ends in a "herk" sound as his hair is pulled for good measure.

"True enough," says the demon, ignoring him completely. "But you're on a deadline. You had it easy before; no one thought Dean was going anywhere. How long do you think it'll take you to find him this time, with all of Hell working to hide him?" The demon, possessing a porcine man with a flabby red face, laughs thickly. "No, you'd better get out of Dodge, or lose your precious little pawn. And don't think about smiting us on the way out, you know you'd level him along with us." He gestures to Dean with the iron.

Castiel is almost glaring, a real achievement for him. Dean can't enjoy it properly, though, because he can feel the first rasps of the blade over his windpipe. He knows he doesn't make a sound, but Cas seems to hear anyway, sharp eyes focusing on him. The angels sighs.

"Close your eyes," he says, quietly, words directed to Dean alone. He does so – the demons, quicker on the uptake than some of their kin, do as well – and then there is a flash of light that sears even through his eyelids. And then, the sound of fabric tearing, and a scream.

Before he even opens his eyes, Dean is moving, is slamming his arm against the hand holding the knife at his throat while he jerks his other elbow back into the demon's gut. It's enough time to get at his knife, and the fight ends then and there.

On the other side of the room, Sam's standing crookedly against a wall, while on the ground two demons return to Hell. The third, still holding the cattle brand, takes one look at Sam's already raised hand and flees in a cloud of black smoke. And, on the ground between them, Jimmy lies rocking on his side, coats torn up the back from hem to collar.

Dean gets there first, puts a hand on the man's arm to hold him still, and pulls aside the strips of cloth. On his lower back a bloody mark has been burned into the flesh there, leaving it red and wet and weeping, symbol the mirror of the branding iron. Dean doesn't recognize it, but it's definitely an occult sigil. Jimmy's keening quietly, muscles and tendons tense as stone under his skin. Sam staggers over to glance down at the mark.

"Shit," he says, quietly.

"You recognize it?" asks Dean, looking up at him.

"No; it's nothing standard."

Dean nods; that he knew already. "Alright, let's get the hell out of here. Jimmy, can you walk? C'mon." He drags the man to his feet by his arms, throws one over his shoulder and leads the man outside. Sam grabs the iron, and follows.

There's not much in the way of first aid for this kind of burn in the trunk, not for something already charred black at the edges with glints of shiny red peeking out from under cracks, but Dean pulls out a couple of ice packs from a tiny cooler and hands them to Jimmy, who drops them. While Sam takes the iron over to the nearest puddle to try to cool it enough for transport, Dean helps the man into the back seat and, when he's as close to horizontal as he can get, pulls the clothes away and presses the ice against the burned skin. Jimmy screams, back arching as if shocked, and then subsides into rough gasping. Dean waits for him to calm some more before reaching around to grab the man's right arm.

"You need to hold the ice on, okay? You hear me, Jimmy? Sam and I'll be up front, you've got to hold the ice on."

Jimmy moans, but his arm tenses enough to keep the ice from sliding off.

"That's right. Stiller you keep it, the less it'll hurt."

He backs out of the door and closes it, to find Sam coming over with the now-grey iron.

"Cold?"

"Good enough." He drops it in the trunk and slams it shut.

"Good. Let's go."

----------------------------------------------------

They're about 20 miles gone when the car starts to shudder, windows shivering in their frames, metal humming. Dean glances automatically at the dash, but there's nothing wrong there, full tank, cool engine, no lights.

"Stop the car," slurs Jimmy from the backseat through clenched teeth, the first thing he's said, causing Dean to jump. The wheel's beginning to buck under his hands, though, so he does as he's told and jerks the Impala over onto the uneven shoulder. Jimmy's out of the car almost before it stops, stumbling unevenly down the shallow incline into the field beside it in a gait which suggests its mostly his momentum keeping him on his feet. The shuddering ceases almost as soon as he leaves.

The field lies fallow now, winter snow having just finished melting to leave them wet and muddy; in the grey afternoon light it is bland and gloomy. Corn was clearly grown the year before, the stalks now chopped off less than a foot above the uneven earth, remnants sticking up like a thousand tiny spears. Jimmy staggers between them, walking in small, stiff movements as though both legs were in casts, his rent coat blowing out like wings behind him. He stops several yards into the mud.

Dean and Sam are out of the car by this point, watching from the edge of the road as the man sets his shoulders and stares up into the cloudy sky. There is no shaft of light, no shower of gold. There is a sound like a sky full of starlings, like electricity humming in wires, like a circuit on overload. The windows of the Impala shiver slightly; Dean flinches. But Jimmy's just staring up at the sky and, occasionally, nodding. After a minute he turns back, and returns slowly through the field, face a mask of pain and determination. The slope at the edge of the road stalls him, feet slipping on wet mud, and Dean reaches out to pull him up to level ground.

"Castiel says he can't come back. The seal's blocking him." The words come thickly, as though he has to concentrate on not biting his tongue. Probably he does.

"So?" asks Dean, raising his eyebrows.

Jimmy looks up at the sky. The answer comes in a sound like a stereo overloading. The windows hum like bees, and both brothers slap their hands over their ears.

"Turn it down, Cas!" bellows Dean, wincing. Jimmy's face twists from pained to afraid.

"He says there aren't many people compatible enough to be vessels, and not many of them would agree to become one anyway," pours out Jimmy, in a quick, distracted tone, hurrying through the message. He turns back to the sky as soon as he's done. "Castiel, please, not –"

Only a brief rattle this time, but Jimmy relaxes, shoulders dropping and causing him to wince.

"What?" barks Dean. Jimmy shakes his head.

"Nothing."

Dean gives him a sceptical look, but continues anyway. "So, Cas can't find a new host?"

"He says it'll take time."

"How much time are we talking about there? 'Just going out for a drink, back in a minute,' kind of time, or 'tell the grandkids to keep an eye out for me' kind of time?"

Jimmy glances up; both brothers wince pre-emptively.

"He's not sure," is the answer. "But he thinks weeks rather than days. Months, maybe."

"Great. Because we totally have that kind of time to spare," says Dean, throwing up his hands. But Sam, who never takes off his thinking cap, comes up beside him and says quietly:

"He has a plan, doesn't he?"

"Yes," says Jimmy, glancing from Dean to his brother and back again. "But he doesn't think you're going to like it."

"That sounds promising," growls Dean. "What is it?"

Jimmy looks up, then struggles back out into the field, a lone man in a dirty trench coat standing against a bleak horizon. He's gone several minutes this time. When he comes back, he's looking at Dean.

"What?" says Dean, defensively, shifting his weight.

"He says," relays Jimmy, coming to stand next to the elder hunter, "he can erase the seal so that he can use me as a vessel again. But to do it, he needs a temporary host."

"Oh, no," begins Dean.

"He says it shouldn't take too long, and besides, it won't be like –" Jimmy pauses slightly, then continues in a duller tone, "won't be like a regular possession. You're not very compatible, so he won't be able to use most of his power. You'll still be in control, he'll just be there too."

"No way," says Dean, immediately. "So much no. This is off the scale of no."

"I'll do it," says Sam gruffly, and Dean swivels to glare at his idiot brother.

"What the hell, man, you want to be possessed?"

Sam raises his eyebrows in a classic you have a better plan? expression. Jimmy cuts in before Dean is required to beat some sense into his brother.

"It doesn't matter. Castiel says it can't be you. Says your blood makes it an impossibility."

Dean doesn't have to be watching for it to see Sam's shields drop like curtain, revealing the stark hurt beneath; it's clear as day. Dean steps into the gap to deflect attention, not the least his own.

"So tell him to find someone else. If it doesn't need to be someone who's on Heaven's Christmas list, then he's got thousands to choose from."

"And of those thousands, how many would agree to it? Angels don't take unwilling hosts, and they don't sugar coat the truth. Much," Jimmy adds, with just a trace of bitterness.

"Damn straight," says Dean. "You'd have to be an idiot to agree. No offense," he says, with a shrug.

"Look," snaps Jimmy, in the first hint of anger they've ever seen in him, "I don't want to go back to it. On my list of a thousand things I don't want to happen, going back to being Castiel's vessel's right down at the bottom. But you know what's under it? Seeing everyone I know die. I'm not going to pretend to know a lot about what's going on, but I know we need every weapon we've got to stop what's coming. We can lose one for weeks – months – and maybe for all I know lose the war, or you can just suck it up and be a temporary host for a couple of hours, a few days." Jimmy's one of the meekest men Dean's ever met, but when he finishes his eyes are bright with just a hint of the strength the hunter is used to seeing in Castiel. Maybe it's the pain, but Dean doesn't think so.

He bridles regardless – he's lived through too many years of shit not to. "Don't you dare tell me I haven't given enough," he begins, which gets out enough of his righteous fury to let him think straight. He cuts himself off roughly, and turns to stare out over the fields. "How long is temporary," he asks, gruffly.

"He doesn't know. He can't get near me to find out without a vessel."

Dean sighs, and turns back. "Fine. But only if he swears to get the hell out if I tell him to."

Castiel may be nothing like Dean imagined an angel to be before he met one – albeit since he stopped imagining them after the age of 7 they were mostly white and fluffy and blond in his head – but he has always kept what few promises he's made.

Jimmy glances at the sky; the brief whine is over almost before it begins. "He agrees."

"Great." Dean spreads out his arms. "Then, beam me up, or whatever." Behind him, he hears Jimmy grab Sam and pull him away behind the shelter of the Impala.

It starts out like a sunrise, the glow weak and warm on his skin. But it brightens exponentially, soon reaching the strength of the noonday sun in a clear midsummer sky. And it grows brighter still, brighter than a spotlight in his face, brighter than lightning, brighter than the fiery corona of the sun. Dean staggers, wrapping both arms over his face, trying to block out the blinding light. The fear of that light, of scorched eye sockets, nearly overshadows the feeling like something's being poured into him through a funnel.

It ends abruptly, a switch turning off, leaving Dean on his knees in the muddy gravel. He feels something like dizziness, but more like confusion. Like he has two sets of hands and feet, and isn't sure which he needs to be moving. That, and a warm weight in the back of his mind, are the only differences.

He stands slowly, finding his feet by trial and error, and as he figures which limbs are real his perception of the others vanish, until he feels nearly normal again.

"Dean?" says Sam, from somewhere to his left. "Dean, are you okay?"

"I'm … not sure," he says. And then, narrowing his eyes, "Castiel?"

Yes, says a voice, says his, Dean's, voice, right behind him. Dean jumps, and swivels to look behind him. Sam is there, looking startled and worried. Behind him, Jimmy is leaning against the Impala's hood, looking only slightly interested.

"Uh, so, you're here."

Yes. You needn't be concerned, Dean. I won't assert control. I won't intrude. Maybe it's just that the angel's not used to his voice; maybe it's just that he's not used to his voice, but the angel sounds coldly unamused by the whole situation.

He knows he's never sounded like such a stuck-up bastard before. He tries to hold on to that thought, rather than the one that's railing against ever instinct his father ever pounded into him, oh god there's something in me there's something in me there's something in me.

"I'm so reassured," he hisses. But… it's true. He can feel the truth of it, like a tangible object. Feel the angel's strength held in careful, absolute check. Like having a tiger drooling on the back of his neck, and knowing it can't break its chain to bite him. Safety that, nevertheless, feels really dangerous.

"Dean?" says Sam again.

"Uh, he's here."

"And you're okay?" says Sam, slowly, as if talking to a shock victim. Dean's not so sure that's a bad assessment.

"At the moment, apart from having an angel in my head," he says with bright sarcasm. He tries to turn to look at Cas, confusing physical and mental again. "How long're you staying?" he asks the Impala.

That depends on the seal.

"Right," says Dean forcing himself not to shiver at the voice inside his head – get it out! – and looks at Jimmy. "Let's see it."

Jimmy walks over and stops when he's passed Dean, then reaches back to gently part his torn clothes to reveal the charred, blackened skin below. Dean's teeth grind together instinctively. There's a slight pressure on his shoulders, as though someone is standing behind him, leaning on them. Dean finds himself leaning back to compensate.

Touch it, says the angel, flatly.

That seems like a bad idea, but whatever the hell gets Castiel out of his head soonest. He reaches out a hesitant hand and brushes his fingers against the raised skin. It's like pressing them against a hot element. "Fuck," he snarls, waving his hand to cool it. In his head, he feels Castiel recoiling, feels a rolling pressure against the far borders of his mind as the angel retreats from the sigil. "I'm guessing that's not good?"

It is unusual, but not unexpected. I apologize.

"Can you fix it?" He'd sure as hell better be able to. Better be able to do it right the fuck now.

Hold up your hand again, close without contact.

Jimmy's glaring over his shoulder now, face pale and drawn. Dean raises his hand again, slower this time, and lets it hover just above the burnt skin.

There's a feeling, like warmth flowing in a thick river, like heat rolling over sand dunes, like a blazing fire on a cold winter's night. It rolls slow and lumbering down his arm and spreads through his palm to his fingers. Dean's surprised, when he glances at his hand, to find that it looks the same as always.

On Jimmy's back, the worst of the black char turns in on itself, like paper burning away into nothing. Some of the flesh knits back together in an angry red mark. It's quite a lot like watching a time-lapse video in reverse. A little of the tension seeps out of Jimmy's ramrod straight form, and he lets out his breath through his teeth in a long hiss.

But the warmth only lasts until the black is gone, and then fades away to nothing, leaving Dean cold and shaking. Trembling.

"Why'd you stop?" he says, but the answer is there in his uneven voice, in the knocking of his knees. He takes a couple of steps back to lean against the Impala, Sam hovering at his side watching him with concern.

"Dean? You okay?"

"Fine," he hisses, even as Castiel answers.

We're not very compatible, Dean. Even projecting a relatively small amount of my power through you is difficult for both of us.

There's no change in the emotionless tone of the angel's voice, but the tiger seems much further away now, the pressure at the back of his mind much lighter.

"So how long'll it take?"

Judging from the questioning look Jimmy's giving him as he gingerly drops his shirt back, he's not the only one wondering.

Perhaps a week. Perhaps less, if you learn to adapt to me.

"A week," says Dean, to the others. Sam shrugs in blank acceptance of the fact, Jimmy sighs; Dean can't tell if he's pleased or disappointed.

"Alright, then, you can take off now. Come back when we're up to it again."

No. Repeated coming and going, apart from quite probably drawing unwanted attention, would possibly be harmful to you.

"Possibly?" says Dean, to cover the painful churning in his gut. To cover his concern. Concern. Not panic. Definitely not.

You are fine, says Castiel in his voice – in him, using him, being him.

"Dean?" says Sam, breaking in.

"He's going to hang around," relates Dean tersely.

"Uh, good. But, we should really get going. We're not exactly inconspicuous out here."

He's right. It's a quiet road, but there aren't many leading away from the old barn, and anyone trying to track them down from there won't have a hard time of it.

"Fine," says Dean, and grabs the door handle. And then, to the back of his head, "Don't talk to me while I'm driving."

TBC