Sam can't breathe.

He's choking, choking on blood and vomit and his own insides and his skin feels like it's slowly being peeled away from the muscle and there's a terrible pressure behind his eyes and he thinks he'll go crazy, absolutely insane, because no one person is physically capable of withstanding this much pain and God he just wants to die, please let him die.

Having fun, Sammy? Lucifer's voice is more like a presence than an actual sound, dark and evil and rotten, and every time he hears it Sam thinks of flayed skin and ripping organs and pain and death and madness—but he can't get away from it, the voice, because it's inside him, echoing in his own skull.

And then his world dissolves into a series of disconnected sensations—his own screams, the knife as it gouges into his flesh, Lucifer's darkevilrotten voice and pain, so much pain, and why why why can't he just die and leave here and never have to do this again, God he can't take it much longer—

"Sam!"

He bolts upright, eyes wild, tangled in sweat-soaked sheets. Screams ache in the air like metal, bright and shiny and piercing, and Dean is there in a heartbeat, hands on his shoulders, on his chest, pushing him down, trying to soothe him. "Shhh, Sam, it's okay, you're not there anymore, you're here, I'm here, shhh…"

The screaming cuts off with a choked noise. Sam presses the heels of his palms into his eyes until fuzzy dots stand out against the blackness and breathes—or tries to, at any rate, tries to slow down his pounding heart and throbbing pulse and aching skull.

There's a creaking noise as Dean sits down at the edge of the bed. He doesn't say anything. Not for ten seconds, twenty, thirty. A minute. Five minutes.

Sam's voice is a whisper, a thread of pain and fear and anxiety stretching between them. "Sometimes—when he was feeling particularly vicious—he would…" He takes a deep breath. "He would—dismember me, slowly, one knuckle at a time."

He pretends not to notice Dean's breath coming faster, the pained look on his face. Dean doesn't want to hear this but Sam has to tell him, has to tell someone because damn it, he can't carry this weight on his own.

"But the worst," he continues, breath catching in his throat, "was when he was mad at me, when I…rebelled. In the beginning. And then he would—he would change his form, I don't know how, and he would be…" Sam swallows. "He would be you. And he would tell me awful things, things like how much you hated me and how awful I was and how I deserved this, all of it, because I was filthy and rotten and evil and just like him, just like Lucifer."

His brother makes a sort of strangled noise. "Sam," he says, a hitch in his voice, "he was lying. Sam, he was lying, I never—I would never say those things, I never even thought…not even close…"

Silence.

"I thought you did," Sam says softly. "Before. When I was with Ruby, when I was drinking the—" His voice cracks. "The demon blood. I didn't understand how you…I mean, I looked in the mirror and I hated what I saw. And for you, after what I did, how I betrayed you—I thought for sure…"

Silence. Words clawing their way out of Dean's throat.

"I never hated you." He sounds like he's choking. "Sam, I never—how could you—I never hated you, not even when you were sleeping with Ruby, not even when you were…I never…" He swallows, passes a hand over his face. "Sam. You're my brother. You don't get it, I don't know…I don't know how to hate you."

Sam breathes out, shuddering. "I do," he whispers, so softly the words barely escape his lips. "Know how to hate you, I mean. You. Me. Everyone."

Dean can't think of anything to say, so he just closes his mouth and listens.

"I try not to," Sam says, desperate and needy and for just a moment he's six years old again, wailing in the dark, and Dean is there to crawl in bed with his baby brother and whisper soft reassurances that it's okay, that nothing's out there, that you don't have to be afraid of the dark. "I can't stand it. I don't know why, I can't control it—I mean you, of all people—and I know I deserve it, I started all this, it's my fault, my fault for being bad—but it's awful, and I don't know…it's something…inside me. Maybe I am. Maybe I am like Lucifer says, maybe—"

"You're not," Dean says.

Sam stops. "I'm…what?"

"You're not," he continues awkwardly, face flushing. "You're not—you're not like that."

Sam stares at him, and his eyes are a plea. "How do you know?"

"Because you…" Dean feels certain, all of a sudden. "You try to fight it. Lucifer, Ruby, Michael, all those people—demons—whatever they are—they don't care. They don't try to—to redeem themselves. They don't hate themselves for it. I mean…" His mouth feels dry. "Sam…Sammy. You're not good."

And there it is. The eternal truth, the one reality he's tried his damnedest to avoid having to face all these years. Ever since Cold Oak—hell, ever since before Cold Oak, ever since Azazel, ever since Dad. His brother, the little boy he raised, the college boy, his demon-blood-addict screwed-up brother—he's not good.

But he tries so fucking hard, Dean feels like it's gotta count for something.

"Maybe you were. Once upon a time, before I dragged you back into this mess. Before—before Yellow Eyes, before Ruby, before Lucifer. Maybe you were then. But Sam—Sammy—" Dean's voice cracks. "Look, I practically raised you. Hell, I know you better than I know me, and you try. You try so damn hard."

And Sam's looking at him in that torn-up way he hates and if Dean's heart was capable of breaking—if it wasn't too hard, too screwed-up, too frozen—he thinks this would be what it feels like.

"And…that's what makes you…not them," he concludes lamely.

Sam breathes like a shudder, more a gasp than anything else, and then all of a sudden he's crying, all the tears he's tried to hold back running down his face, and Dean doesn't know what to do because he thinks if Sam cries any more he'll start crying too, and he doesn't want that, so he just closes his eyes and waits.

Eventually Sam stops. If it was a normal day, if it was just some stupid breakdown in a crappy motel room after a tough hunt because all of a sudden it just feels like too much (and Dean knows how to deal with those, because it's happened before, happened to him), he probably would have made some stupid crack about chick-flick moments and poured an extra glass of whiskey—but this isn't normal, and so he doesn't.

"Remember how it used to be?" Sam asks suddenly, taking him off guard. "Playing pool, running credit card scams. Driving around in the Impala—you know, saving people, hunting things."

Dean can't breathe. He wonders if Sam knows that those are the exact same words (saving people, hunting things) he used when he was trying to get his brother back into the business all those years ago.

"Yeah," Dean croaks out. "I remember."

Sam's fingers are twisted together, scratching at his jeans, at the bed, picking at his fingernails. His knee is tapping nervously on the floor. Dean notices his brother moves a lot more ever since he got back his memory—it's as if he can't stop, can't calm the bundle of nervous energy inside him because the minute he stops moving he'll remember. Even in sleep he isn't quiet, always twitching and whimpering in the throes of nightmares.

But right now, for just this moment, Sam is still. Dean is so used to the constant movement that he almost feels sick just looking at him—like a sailor unused to solid land after months of rocking with the waves.

Sam's eyes are desperate. "Do you think we can go back to that?"

For a long moment, no one speaks. Dean is thinking, Sam is waiting, and the clock is ticking mournfully in the corner. Another bloody hunt, another greasy room, Dean trying to blot out the memory of Cas and God and Crowley and most of all Sam from his mind with blood and monsters, Sam just trying to make it through the day without slipping back into Lucifer's grip, the vise-tight hold of his memories.

He hasn't thought in a long time, but now he thinks.

"No," he says at last, and hates himself for a brief moment as Sam's face goes slack with shock and disappointment. "We can't go back. It's not…the same." Too much has happened since then—too much blood, too much betrayal, too much grief. Dean's memories of those days in the Impala feel a lifetime away, like watching a video of someone else's life.

"But maybe…maybe it doesn't have to be." He watches Sam carefully, tries to gauge his brother's reaction as he prays to himself that Sam will understand.

Sam looks up, and Dean can practically see the gears working in his head. "Different," he says slowly, "but…still good?"

A relieved breath escapes Dean, a wave of pride rushing through him because damn it, this is brother we're talking about, Stanford Sam, college boy—and even screwed-up, ruined, and tainted with sin, even as just a sliver of his former self, even crazy and corrupted and broken as all get-out—this is Sam, and he understands. His brother is rusty, but he has always been smart.

"Yes," breathes Dean, and then, louder: "Yes. Exactly. Different…but good."

Sam nods. He takes a deep breath and meets Dean's eyes for the first time in days, and Dean feels like crying when he sees—it seems so simple, but God it hits him hard—that Sam's eyes are the same, same as they always were, same as they were when he broke his arm when he was eleven and when he ran off to Stanford when he was eighteen and when he pored over maps in that greasy diner when he was twenty-two, the first time in years Dean looked at him and thought home, and same as they were when he was twenty-seven and he told Dean that he wanted to give himself up to the Cage.

"I can do that," he says sincerely.

Dean nods, looking at him. "Okay. Okay," he says again. He takes a deep breath, and then another. "We can try that."

Sam nods, and feels the beginnings of redemption in his soul.