Title: Cut With Our Own Dust

Prompt: From a prompt by the lovely and talented khakigrrl: Burns, tattoos, skin carvings, Enochian symbols... there are a lot of ways to keep demons and angels inside or out of your skin. Sam discovers an intricate symbol that will allow him to wrench back control from Lucifer. Now he just needs someone to carve it into his back.

Spoilers: Up to 5.18, but really, all of Season 5 is fair game.

Word Count: 2,841

Warnings: Mutilation, lots of blood.

Disclaimer: Let's just say that if they belonged to me, they really wouldn't be in as good physical condition as they are now.

Neurotic Authorial Disclaimer: Umm, so I whipped this up during a night shift, and now I'm having writer's remorse and feeling all angsty about it. I dunno. I loved the prompt, not sure I did it justice. It kind of went differently than how I expected.

Neurotic Authorial Disclaimer #2: As usual, no beta, no revision, no nothing. Read at your own peril. I hereby disclaim any responsibility for psychological scarring that results from reading this fic.

Author's Note: The title is taken from a quote by John Webster.

Cut With Our Own Dust

Dean finds Sam sitting cross-legged on the floor of their motel room, clad in jeans and a soft, faded grey t-shirt, bare feet tucked under his knees. Castiel is sitting on the bed before him, ankles together, hands resting on his knees. He's shucked the trench coat, but the rest of his suit is the same, tie hanging slightly askew from his collar.

"You could cut the tension in here with a knife," he says, to fill the silence. "Or a box cutter, apparently," he adds, noting the tool that Sam is cradling in his lap along with what looks like one of Bobby's old books, a slim, leather-bound thing with arcane symbols carved into the cover. "Cas, is that the same—"

"Yes," Castiel says curtly, not tearing his eyes away from Sam, who keeps his own head ducked down, not meeting either of their gazes. Dean swallows. That can't be a good sign.

"Someone want to fill me in here? Cas? Those wounds of yours healing up okay?"

"I am fine, Dean," the angel replies, a hint of exasperation underlying the words, and Dean purses his lips. He can understand that Cas is probably sick of his hovering, but it's not every day an angel of the Lord has a banishing sigil carved into his own chest and blasts himself to Kingdom Come in some horrifically misguided eleventh-hour Hail Mary to avert the apocalypse.

Sometimes, if Dean closes his eyes, he can still see the angel's flesh yielding beneath the blade, feel the blood —warm and just a little tacky— coating his fingers. The angle had been all wrong for Cas to do it himself, and Dean had felt more than a little sick at the thought of slicing into the too-white skin. It had been Sam who'd done it, in the end, while Dean held the angel still, pressing on his shoulders to keep the level of injury to a minimum.

"Okay. So what's going on then?"

Sam keeps his gaze trained on the dingy motel carpet, turns the yellow plastic sheath of the box cutter over and over in his fingers, as though trying to memorize its contours. "I found a way for my plan to work."

"It's foolish," Cas snaps. "Reckless."

"I wouldn't call it reckless, exactly," Sam mutters.

"Insouciant, maybe?" Dean can't help himself, blushes when both turn incredulous stares on him. "Sorry. What are you talking about?"

"I found a symbol —a sigil, really— that'll give me control long enough to get Lucifer caged. Permanently."

"No."

"Dean..."

"I said no."

Sam raises his head, eyes flashing dangerously. "You have a better plan, then? We have all the rings now, Dean, and no other way of getting the Devil to play ball. We either do this my way, or else the apocalypse plays out the way its supposed to, and the planet gets torched. Tell me I'm wrong," he challenges, but he's looking at Castiel, who abruptly looks away.

"Cas... is he right?"

Castiel shrugs, a gesture that's so human that for a moment Dean's breath catches in his throat.

"Yes, I'm right. Dean... Bobby died for this. Everyone we know—" there's a hitch in Sam's voice. "Help me make this right. This will work. It'll bind Lucifer to me, and we can lock him away, permanently. Please. Castiel, you know I'm right."

Castiel's silence is more telling than anything he could say, and Dean blows out a breath, rubs the back of his neck. "Okay. So what's this thing look like?"

Sam flips open the slim volume on his lap to a two-page spread, hands it over to Dean to look at. He can't really make heads or tails of it. It's similar to Enochian, as far as he can tell, but his Enochian is rusty at best, and it doesn't look quite right for that, anyway. What it is, is complicated-looking, all intricate whorls and symmetrical patterns, circles within circles, pentagrams within pentagrams. He halfway expects to find the logo for BOC in there, is kind of disappointed when he doesn't.

"We have to go back to Ilchester," Sam is saying, when Dean remembers to pay attention again. "It's the logical point of access, and the convent's been condemned, so we don't have to worry about getting interrupted."

Dean nods. "Fine. But the minute this looks like it's going South on us, I'm pulling the plug, you hear?"

"Fair enough," Sam gets to his feet in one fluid motion, tucks the box cutter into the back pocket of his jeans, and not for the first time Dean finds himself wondering when his gawky little brother went from being all awkward long limbs to this powerful giant of a man. "We should get going. Get this over with."

They leave South Dakota without looking back once.

There's a pall hanging over St. Mary's Convent in Ilchester. Dean remembers Missouri's words about psychic wounds, and resists the impulse to shiver in horror as he steps over the threshold of the chapel in which Sam set Lucifer free, practically a year ago to the day. Castiel stands directly behind his right shoulder, grim-faced and tense, hands clenching and unclenching by his side. The gesture appears to be entirely unconscious.

Sam is carefully setting out a few basic tools of the trade on the cold flagstones. He hasn't said much in the past day, silent except for when speaking is absolutely necessary. He's tossed his denim jacket to the side, is now clad in only the same clothing he was wearing when he first told Dean about this plan. With the apocalypse raging all around them, there hasn't exactly been time to find new clothes at local thrift stores. Orange spray-paint strikes Dean as faintly sacrilegious in a church, but then, this one has already been defiled in the worst way possible. What's a little orange spray paint compared to the spilled blood of half a dozen demons and the presence of Lucifer himself?

"Is that a devil's trap?" he finds himself asking, staring at the familiar pattern on the floor. Sam has traced it a little larger than usual, but it's unmistakable, and in no way bears any resemblance to the intricate sigil Sam showed him before.

Sam nods. "Yeah."

"What about that sigil thing? I thought that that was the whole point of this little field trip."

"It is. I just have to finish this first."

Silence falls again as Sam works. He doesn't ask Dean or Castiel for help, and neither of them offer. Dean gets the sudden ridiculous, horrible feeling that they're holding a vigil of some kind, bearing witness to something so damned huge it won't fit in his mind. Cas places a firm hand on his shoulder, and he feels the tension in his body ease a fraction, at least until Sam carefully takes off his boots and socks and pulls his grey t-shirt over his head. He folds it carefully, rolls up his socks and tucks the bundle into one of the boots, shoves all of it against the wall, out of the way. He pulls the box cutter out of his pocket —Dean had all but forgotten he even had it— and Dean can see the unsteady rise and fall of his chest as he takes a steadying breath.

"Right. Let's do this."

Dean's blood runs cold as he realizes what Sam hasn't been telling him. "No. No way. You son of a bitch, there is no way, and you knew that going in, or you wouldn't have kept it from me!"

Sam looks past him at Castiel. "You agreed," he says simply. "There's no other way, so let's not make this harder than it is, all right?" He slides the blade out with a quiet snick, flips it deftly in his hand, and holds the handle toward the angel.

Castiel steps forward to take it, but Dean intervenes, puts a hand on the angel's wrist, stopping him. "No."

"Dean, please."

He shakes his head, stares Castiel in the eyes. "I can't let you hurt my brother like that. Not anyone, not even you."

A beat, then Castiel nods, understanding written in every new line in his face. "Very well," he replies, and steps back.

"Dean, come on. You—" Sam stops abruptly, his face draining of colour, as Dean turns and holds out his hand, palm up.

"If we're going to do this, it has to be me. I can't..." he forces his voice not to break. "I can't watch while someone does that to you, Sammy. Give it here."

"Are you sure?" it comes out quiet as a breath. "I didn't want to ask you. Not after—"

"I know, and yeah, I'm sure."

"Will you be okay?"

"No, probably not," he swallows as his throat threatens to close up. "But there's no one else to do it."

His hand closes around the yellow plastic. It's rough against his palm, feels deceptively light. Sam turns away, drops to one knee inside the devil's trap before lowering himself to lie face down on the cold floor, arms folded beneath his head, and Dean understands now why he drew it larger than usual. He can see the outline of Sam's muscles just beneath the expanse of skin, already mottled and pocked with countless small scars —the price they pay for the life they lead, exacted in flesh. Sam takes one last deep breath, lets it out slowly.

"Do it."

Dean opens the small book to the right pages and, careless of the book's integrity, cracks its spine so that it'll lie flat. He kneels between Sam's legs, blade gripped loosely in his right hand. It feels familiar and alien all at once, as he calmly surveys the flesh laid bare before him, coolly appraising the best place to start. There's no margin for error this time: up here, reality is too concrete, and Sam's body won't knit itself together at the end of the day. He reaches up with his left hand, places it flat between Sam's shoulder blades and holds it there for a moment, feeling his brother's heartbeat flutter against his palm, waits until it slows a bit.

"I'm starting now," he tells him, warning him.

This isn't a sudden pain, one that's best dealt without warning. This will be an exercise in patience. Dean places the tip of the blade at the nape of Sam's neck, presses just enough to draw blood, watches to see if his brother will flinch, nods to himself when he doesn't, then presses harder, drawing the blade down in a fluid sweeping motion.

He works in silence, trying not to think of all the times he's stitched up lacerations in his brother's skin, splinted broken bones, rubbed antibiotic ointment into burns. He's always talked Sam through all his applications of first aid, his mouth running away with him in an effort to mask his anxiety, trying to distract his brother from the pain long enough for the painkillers to kick in. Now, though, there's nothing to say, nothing that will make this more bearable for either of them, and so he stays silent.

There is nothing of hell in what he's doing, in spite of his fears. Here the goal isn't to inflict anguish, to break the man under his knife. Sam doesn't scream, doesn't so much as whimper; is utterly still as Dean cuts into his skin, the only sign that he can feel anything at all the sheen of sweat that's appearing on his body, the slight quickening of breath, the way his knuckles turn white as he clenches his hands into fists, fingernails biting into his palms. The world has shrunk to just this circle, to Dean and Sam and the bloody blade that's still sharp enough to split the flesh with only a minimal amount of pressure. Blood wells up in the cuts, beads in the places where he inadvertently pressed harder than others, trickles slowly in rivulets along Sam's skin, drips into tiny pools on the flagstones beneath them. Just once Sam flinches, hissing through his teeth, and that's when Dean has to cut across the thick scar at the small of his back —where Jake Tully buried his knife up to the hilt three years ago— and Dean murmurs an apology, rubs his thumb over the scar without thinking, smearing the blood there before resuming his work.

The scar disappears under a welter of blood.

He doesn't know how long it is before he inflicts the final cut, before he stands slowly, waiting for the circulation to return to his legs. He crouches at Sam's side, smooths the hair away that's plastered to his forehead with sweat, leaving another small smear of crimson that will soon dry, turn brown and crumble away, as though none of this never happened.

"Can you get up?" he asks, voice barely above a whisper. Somehow it feels wrong to speak even in a normal tone.

"I might need a hand," Sam says faintly, and Dean almost laughs as he sees the sheepish smile on his brother's face.

"No shit. Come on, Sammy, gimme your arm," he says, and it almost feels like old times as he pulls Sam to his feet, steadying him, except this is so far from normal that he's pretty sure that when he stops feeling so damned detached from it all that he's going to vomit everything he's eaten for the past month. For a moment Sam stays half-collapsed in his arms, legs refusing to take his weight, sweat trickling along his hairline, face deathly pale. Then he makes a visible effort to pull himself together, straightens up and lets go of his brother.

"We should probably do this before I pass out from blood loss," he says with a small smile, and Dean shakes himself.

"Right. What now?"

"Rings. One at each point of the pentagram, except for one, obviously. That one stays empty, symbolizes the head of the..." Sam falters, and Dean puts out a hand to steady him.

"Okay, you can tell me about the symbolism later. I'll get the rings."

It seems ludicrously easy to just lay out the four tiny rings after everything else, but Sam flashes him a smile that both terrifies and reassures him. In this, Dean has no doubt that his little brother knows exactly what he's doing: he's always been the more detail-oriented of the family, the one who understands the nuts and bolts of ritual, the why as well as the what and the when and the how. He straightens up from where he's bent over to place the last ring, Sam at his elbow, and his brother nudges him.

"You need to be outside the circle, Dean," he says, jerking his head to emphasize his point.

Then he claps a hand on Dean's shoulder, and all but pushes him toward Castiel, who's still standing stock-still by the solid oak doors of the chapel. With a twinge of guilt Dean realizes he'd forgotten the angel was even there, and he grimaces apologetically at him as he steps out of the devil's trap and turns to look back at Sam, who moves to stand in the exact centre of the pentagram, facing them. He looks calmer than Dean would be in the same position —and Dean knows what he's talking about in this case. He looks up at his brother with a shy smile that reminds Dean of when he was eight years old and landed a small but important role in a school pageant, standing very straight and trying so hard not to show how nervous he was, and Dean was so proud he thought his heart was going to burst. Sam blinks hard, bites his lip for a moment, then squares his shoulders, and too late —always too late— Dean realizes exactly what he's doing.

"Lucifer!" Sam calls out, his voice strong and clear. Not a moment's hesitation. "I accept. Yes."

The ground trembles beneath their feet as the air is filled with the shrieking sound of white noise that always heralds the imminent arrival of an archangel, and a hand takes Dean by the shoulder in a grip so strong he's powerless to resist. Castiel pulls him into his arms, spins them both so that he's between Dean and the sudden eruption of white light emanating from his brother's body, shielding him from the blast.

"Don't look," he breathes into Dean's ear. "Don't look."

Everything falls still. When Dean is able to see and hear again, his brother is gone.