Sam's head fell forward into his hands and his shoulders sagged.

"Hey!" Dean said. "You gonna pass out on me?"

Sam moaned and mumbled something into his hands. Dean sat down beside him on the bed and leaned close. "Can't hear you in there, man. You okay?"

Sam shook his head, dropping his hands and staring down hard at them. "… sorry." He said at last, miserably, his mouth twisting into an awful parody of a smile that might also have been Sam's attempt to fight back tears.

"What the hell are you sorry for?"

"I didn't… want you to see…"

"See what, Sam? See Lucifer? You don't have to worry about that. I mean, it's not like I actually saw him, but even if I—"

"No, I…" Sam drew a shuddering breath and dug the heels of his hands into his eyes before continuing. "I tried not to… I tried to be stronger than that. You would have been stronger. I didn't want you to see me… like that. You know? I just—I'm sorry."

It took so long for Dean to respond that Sam was afraid he wasn't going to say anything at all. He lifted his head and looked at Dean searchingly. Dean was staring at his own hands, frowning. "Dean?" Sam said at length.

"You really think that? You think that I'm stronger than you?"

Sam shrugged. "Yes," he admitted.

"Sam…" Dean's voice sounded low and harsh. "Hell was… Hell broke me, Sam."

"No, it didn't."

"Don't tell me it didn't. It did. I gave up. I gave it up after just forty years of what must have been like a fucking cakewalk compared to what Hell was for you. I just handed it over. Whatever it was—I don't know, decency, humanity, whatever it was that I couldn't manage to hold on to—" Sam opened his mouth to protest, but Dean cut him off. "Don't, Sam. Okay? We don't have to talk about it, hell I don't even know if you can talk about it, but Sam. You were locked in that cage for almost two hundred years while I walked around up here with my head up my ass. I can't ever forgive myself for that. And whatever that did to you, it's my fault, Sam. Mine. That's on me. So don't you ever sit there and tell me that I'm a stronger person than you because if it had been my soul in that cage all this time, there would be nothing left of me but dust. Ashes and dust."

Sam said nothing for a long time. Flashes of memories of the cage played through his head, each one still carrying the sharp pain of a fresh wound. "I don't… think you can compare it like that," he said softly.

"Probably not. But it's true, Sam."

"Dean, I..." He didn't want to say what was coming next, but he needed Dean to know it. "I couldn't have made it without you, in Hell. Even when you're not—when you weren't – there, with me, I still had you to believe in. I needed that. You can never know—" Sam broke off, his voice unsteady. He shook his head before continuing. "I held on… because of you. You're my brother, you always looked out for me. You were always there."

"Yeah well, I guess I fucked that one up, didn't I. Let the one person I was supposed to protect—"

"Dean. You had to let me jump."

There was something in the quiet, certain way he said it that brought Dean to the verge of losing it. He stood up and paced across the room, scrubbing a hand over his face.

"I didn't have to do anything. That was the whole fucking point of the whole 'team free will' thing, right? I made that choice—"

"No, I made that choice."

Dean stopped and looked at Sam whose face suddenly looked too sharp and drawn in, and suddenly he saw not just the little brother he cared so much about but also the weight of destiny and two hundred years of unimaginable torture.

"Dean… " Sam said softly, "I'm sorry."

And then, it was like somebody flipped a switch or pulled back a curtain. A light went on. Dean got it. He understood. Fuck. Because this was Sam, and if there's one thing always Dean got, it was Sam. Even when Sam was being completely stupid and irrational, Dean got it.

"You're punishing yourself," Dean said.

Sam said nothing, just looked down at his hands.

"For... for what, Sam? Tell me. This whole thing with Lucifer, it's because you can't let it go, can you? You think you deserve all this."

Sam shook his head. But it was a lie, Dean saw it. He saw the way Sam's shoulders drew in slightly and the way his posture went the tiniest bit more rigid, and the way his breath caught ever so slightly as he inhaled.

Dean closed the gap in the room between them and heard himself practically shouting at his brother. "That's it, isn't it? Two hundred years of Lucifer and Michael, and you still come away feeling like it wasn't enough. I suppose you think I should have just left you there to rot, is that what you're telling me?"

"Dean, I swear, I—"

"Cut the bullshit, all right?"

Sam exhaled. "Fine. Yes. I guess so."

"So why, then?"

"Because of you."

Dean looked like he'd been slapped. "Because of...?"

"I let you down, Dean, I always let you down. It was always me, being me, screwing everything up, getting it wrong. I… I should have been… I don't know, stronger. Whatever. Dean, it doesn't matter. The point is, every time Lucifer shows up, I tell myself this time I'm going to hold out, not give in, because you wouldn't. And it's never enough. He always finds a way to…" Sam pressed his lips together, something in his eyes going blank and distant.

Dean felt sick to his stomach. Both at the thought of his brother being repeatedly dragged to the breaking point and at the idea that he was measuring himself against some bullshit mark of superiority that Dean supposedly held over him.

"Sam," he said. "Sam, none of that is true."

Sam shrugged.

Dean stood in silence for a while, the muscle on the side of his jaw twitching. Finally he said flatly, "I don't know how to fix this."

"I'm not asking you to."

"So—so what then?" Dean held his hands out in front of him. "We're at an impasse?"

"Apparently."

Dean dropped his hands. "An impasse." He came over and sat down heavily on the bed beside his brother. Sam continued looking at his lap. At length, Dean said, "You, ah… you know what a pain in the ass you are, right?"

That drew the faintest of half smiles from Sam. His pained look softened just a bit, smoothing back into the familiar lines of Sam's face that Dean knew so well. "Jerk," Sam muttered.

Dean would take that as a win.