Warnings: oblique references to torture. Explicit references with withdrawal and violence (canon-typical). Language.

Notes: Slightly AU after Lucifer Rising. Title comes from the Paramore song Let the Flames Begin. Brief quotation from Dickens' A Tale of Two Cities. Enjoy, and tell me what you think.

Sam can't stop shaking. He feels like he's been shaking for days, for years, but he knows that it's only been a few hours. The detox is messing with his head. He shoots a quick glance at Dean, who's pretending to be busy on the other side of the room, his back rigid with tension. He's stalling. He's been stalling for two days, ever since he dragged Sam from that church.

Sam is sickly grateful that, after everything, his brother is still hesitating – but he can't stand it. Can't stand the anticipation, can't stand the withdrawal threatening to tear him apart, can't stand the thought that he might not even be himself when Dean finally finishes the job, can't, can't, can't. Dean deserves his patience, deserves to take all the time he needs, but Sam isn't strong enough. Sam has never been strong enough.

As steadily as he can manage, he pulls his gun from the small of his back. It is a far, far better thing that I do . . . He banishes the thought. There's no martyrdom here, no redemption at the end of a wasted life, and he's not naïve enough to hope for rest. There's only one last act of destruction at the outer limits of the swathe of devastation that is his existence.

He clears his throat, tries to speak, fails. A small, choked sound is all that escapes his lips. Dean ignores it.

"Dean." He hears his voice as if it's someone else's. Dean twitches.

"What?" he snaps without looking around. Sam swallows.

"I – I know you don't owe me any favors –"

"Damn right I don't."

Sam flinches, forces himself to continue.

"Could we just – please –" His voice breaks and he hates it, hates his weakness, hates himself. "Can we please just get this over with?"

At last, Dean turns.

"What –" His eyes land on the gun, and he freezes. "Sam?" he prompts cautiously, fear in his eyes. Does he – god, does he really think Sam would shoot him?

Of course he does. Sam's already proven that he's dangerous, that he can't be trusted. He feels sick, can't speak, can't even look Dean in the eye. He drops his gaze and holds out the gun, barrel pointed at his own chest.

"What the hell am I supposed to do with that?" Dean demands, and his voice is shaking, he's so angry.

Sam's heart sinks. He'd thought – he'd hoped –

Stupid, stupid, stupid. Of course Dean's angry. Furious. After everything that's happened, everything Sam's done, of course Dean wants to make him hurt.

Monsters don't deserve mercy.

"Sam," Dean presses, and Sam realizes he hasn't moved. Wordlessly, he puts the gun to the side, turns to pull the knife from beneath the pillow. He put it there automatically, thoughtlessly, even though he'd known he wouldn't need it. He offers it to Dean. His hands are shaking worse than ever. He wishes they'd stop.

Dean takes the knife. Sam tries not to flinch. There is a long silence, or maybe it just feels that way to his ravaged mind.

Sam clears his throat.

"Do you – uh –" He doesn't know the protocol here, thought Dean would have taken control by now, feels absurdly like a teenager fumbling his way towards sex for the first time. "D-do you want me to – to take off my sh-shirt, or – or lie down . . . ?"

There's another pause, too long for hesitation. Maybe Sam misread Dean's delay. Maybe it wasn't reluctance, but anticipation. Dean has always had a thing for vengeance, and never has his wrath been more justified.

"Okay, Sam," says Dean steadily. "I'm going to ask you something once, and you're going to answer."

Sam nods miserably.

"What. The fucking. Fuck. Are you talking about?"

Sam jerks his head up, startled, confused. Dean is standing in front of him, knife in hand, but it's hanging limply at his side, not remotely threatening. His face is tired and angry, but it's not the cold fury Sam was dreading. It's just irritation, mixed with bewilderment.

"I—" Sam shakes his head. He doesn't understand. He can't think. "Don't you – I mean – didn't you want to –"

He can see the moment Dean gets it. His face goes white, then green, and the knife clatters to the ground as he bolts for the door. Sam remains where he is, frozen, uncomprehending. He can hear retching outside. Dean is throwing up in the bushes. Nothing makes sense.

He sits there, shivering, until Dean returns. He stops just inside the doorway. He's shaking too.

"Sammy," he says, and it sounds like a moan of pain, like the keen of dying animal. He moves forward waveringly, step by step, until he's standing in front of Sam. He reaches towards him, flinches when he flinches but doesn't stop until his fingers meet skin. His touch is warm, gentle beneath his trembling. Sam doesn't understand.

"Sam – oh god, Sammy. How could you – god. Oh god."

Dean sinks to his knees. His thumbs brush the tears from Sam's cheeks, his fingers caress his neck and his jaw, and Sam doesn't – he doesn't –

Dean's grip suddenly becomes vicelike, and for a horrible instant Sam is certain he's going to snap his neck, but Dean only forces him to meet his gaze.

"I would never do that, Sammy. Never to you, you understand? I'd die first."

Dean's so fierce, so sure, eyes blazing, hands strong, and Sam is floundering, grasping desperately for something solid, for anything he can understand –

"But – you're still – you're still gonna k-kill me, right?"

Dean's hold loosens, face stricken.

"No. No, Sammy, no. God, what did I – why the hell would you ask something like that?"

"I—" Sam can't make the words form. His head is filled with thoughts but he can't force them into sentences. "The – you called me –"

"Yeah, I know what I called you," says Dean tightly. "It was out of line, and I'm sorry. But you got that I was gonna kill you out of that?"

"No, I –" Sam squeezes his eyes shut. God, his head. But he needs to make Dean understand. Needs to make himself understand. He opens his eyes again. "The voicemail. You left me a voicemail."

". . . Yeah," says Dean slowly, after a long, empty pause. "I know. I said I was pissed, but we were still brothers. I fucking apologized, man."

Sam stares at him. He's serious. Earnest, even, and Sam never thought that was a word he'd associate with Dean. But – but –

"No. You said – you said I was a monster. That you were done trying to save me."

There's another beat of blank staring before something clicks for Dean. Suddenly, Sam's brother is on his feet, cursing viciously. His fist connects with the wall, leaving a dent in the plaster.

"—those motherfucking sons of bitches I'm gonna kill them I'm gonna deep fry their wings and serve them with barbecue sauce I'm gonna rip their fucking lungs out –"

"Wh-what –?" Sam questions weakly, and he's not used to this, not used to being the one a step behind, but his brain isn't working, he doesn't understand–

"They messed with it, Sam," says Dean, still fuming. "The angels messed with the fucking voicemail. Zachariah said something about 'giving you a nudge,' that fucking bastard –"

"You mean – you didn't –?"

Sam feels like the world is tilting on its axis, and maybe it's the detox but maybe it's because he's spent the last two days thinking his brother wanted to kill him and he'd accepted it as his due but now Dean is saying that he was wrong and he trusts Dean, he does, but he doesn't understand –

His head aches; he's choking on the lump in his throat; the shredded, blackened pieces of his soul are already burning in hellfire. He hears Dean let out a strangled curse and strong hands catch him as everything goes black.

.

.

.

When Sam wakes up, he's not in the motel anymore. The room still smells like alcohol and Dean, but the sheets are soft and clean, the mattress old but not thin. Bobby's. Without moving or even opening his eyes, he takes stock. He doesn't remember finishing the detox, but he must have. His mind feels clear, dreadfully clear. His body is exhausted, but under his control. He's not shaking.

"Hey," says Dean, and his tone is soft, softer than it's been in ages, but Sam tenses anyway, his eyes snapping open.

Dean is sitting in a chair beside the bed, watching him. He looks even worse than Sam feels, face pale, circles under his eyes. His expression is inscrutable, and Sam's stomach turns. Has he been rethinking his position? Did watching Sam's second detox change his mind? Is he just waiting to make sure Sam's lucid enough to understand his reasoning before he puts him down?

Sam begins to push himself up. Dean reaches forward to help. Sam doesn't mean to, really he doesn't, but he flinches, and Dean's face collapses for an instant before it goes blank again.

Uncomfortably, Dean clears his throat.

"How're you feeling?"

"Fine," Sam says, or tries to say, but his throat is like sandpaper and he ends up coughing, instead. Mouth tightening, Dean presses a glass of water into his hands, and he drinks gratefully. "Fine," he repeats, successfully this time. "I, uh . . . I don't remember much."

Dean nods.

"Yeah, seemed like you were kinda . . . out for most of it."

There is a long, awkward silence. Sam's skin is crawling with uncertainty. There are tremors starting in his fingers again, and this time he knows it's not the detox.

"So, uh." Dean shifts in his chair, clears his throat again. "Do you remember what we talked about, uh, before? About . . . why I called you?"

Warily, Sam nods. Dean drops his gaze, fidgeting. He's going back on it. He's going back on it and he feels bad because he lied to Sam and he doesn't like to do that but the detox reminded him of what Sam really is and he wants to explain and look at Sam and have him understand and Sam does understand, he does, but he wants to scream and cry and fight because you can't just tear someone from the gallows and then tell them they have to walk back up themselves because you made a mistake and –

"You get that I meant that, right?" says Dean, derailing Sam's swiftly accelerating train of thought.

". . . what?"

"That we're . . . y'know. That we're brothers. No matter what. And I wouldn't –" Dean looks up, and when their eyes meet Sam is startled to find that Dean's are glistening with tears. "I wouldn't hurt you, Sammy. You have to believe that."

Does Sam believe that? Dean's so sincere, so distraught that Sam could even consider the possibility. Sam can see how deeply it cuts him. But he remembers fists hitting flesh, words hitting home. And really, when it comes right down to it, Dean is a hunter. And Sam is a monster.

He's been silent too long, or maybe Dean can just read the doubt in his face. Dean drops his face into his hands.

"God. God, what can I – shit. Shit. How did we –"

Dean's crying, Sam realizes with a jolt. Weeping with quiet, hitching sobs. Over him.

And really, when it comes right down to it, Dean is his big brother. And Sam is his little brother.

Dean stills when Sam's cautious hand finds his shoulder.

"Dean, I . . ." He trails off. He's always needed words for reassurance, but Dean's not like that. Instead, Sam silently extracts himself from the covers and pulls his brother into an embrace, dropping his head onto his shoulder like he did when he was still the short one. When everything was simple, even if it didn't seem that way at the time.

Dean's hand finds his hair, begins to stroke it in a soothing, rhythmic motion. Sam's not sure who's comforting whom. Sam's not really sure of anything anymore. Tomorrow, they might be at odds again. Tomorrow, the world might burn. But tonight, Dean's heartbeat is steady in his ears, and that, Sam understands.