When Sam mentions the Cage, Dean’s first reflex is immediate dismissal. “Not gonna happen.” Almost like one of Dad's orders, curt and gruff and final, an end to the discussion.
Only that's never really worked well with Sam, has it?
The ride back to Kansas is long, and Sam spends most of it dozing or staring into the dark outside or possibly praying again, who the hell knows. Meanwhile, with each mile the Impala swallows up, the pit inside Dean’s stomach is growing. Something is rising inside him, slow and inevitable like the tide, and he won't be able to stave it off forever. But for now, he keeps it under wraps somehow, even holds it together long enough to fix them some dinner when they get back.
His palms are sweaty and his leg is jumping nervously under the table as they eat, but Sam doesn’t seem to notice, lost in his own thoughts.
"Thanks," Sam says when he’s done, standing up. “Night, Dean.”
Dean watches his brother head out of the kitchen. “Night, Sam.” His voice is steady, but his hands are shaking when he’s placing their dirty plates into the sink, and he knows for a fact that if he tries to wash the dishes, he’s going to break something and Sam will hear the clatter and come back and then they’ll have to talk, and Dean absolutely can’t handle talking about this now.
Hell, he can’t even handle thinking about it, has locked the thing away in his mind, but it’s too big to be held back and ignored, and now it’s crashing its way right through the defensive wall Dean had to build inside his head.
The wall. God, does everything have to remind him of what happened to Sam? Of what will happen again if he decides that there is only one way to stop the Darkness?
Sam, jumping into the Cage.
Dean rushes out of the kitchen, not even bothering to turn off the light as he all but runs through the bunker’s corridors until he reaches his room. He slams the door shut behind him (you want privacy, close your door), turns the key, leans against the solid wood because his legs are suddenly betraying him, overcooked spaghetti soft. No wonder they can’t hold him up, shaking and dizzy as he is now. In a somewhat controlled fall, he drops to the floor as another memory attacks him.
Sam, lying in Bobby’s panic room, screaming as his mangled soul is shoved back inside him.
Even sitting down, back resting against the door, Dean can’t catch his breath. His heart's beating as if he just ran a marathon, so hard that it feels like it’s going to burst right out of his chest. Panic attack, his brain supplies, recognizing the sensation Dean became far too familiar with after he came back from Hell. And even though he hasn't had one in years now, he’s witnessed his share of them on the job since then, helped people get through them, helped Sam get through them –
Sam, curled into a ball in the corner, whimpering like a wounded animal as he relives some past horror inside his mind.
He can’t breathe.
Sam, locked up in a psychiatric ward, gaunt and pale, resigned. “I’m too tired.”
There are black spots in front of Dean's eyes, darkness closing in, chilly, seeping into his bones. He’s going to pass out if he doesn't snap out of it.
Deep breaths. Deep breaths. Deep breaths, Sammy, he used to say, rubbing his brother’s back, talking to him until he’d see recognition in Sam’s fear-wide eyes, and then he’d give an encouraging smile, pat Sam’s sweaty cheek, brush damp hair away from Sam’s face. You’re not down there anymore, Sammy, you got out. We got you out.
And he’s not letting Sam go back there ever again.
“You hear that?” He croaks out, looking up at the ceiling. “You better stop sending my brother these visions before I end you.”
He may be nauseous and trembling and pathetically weak right now, but he is dead serious about the threat and so should be whoever – or whatever – is sending these visions to Sam. Dean’s the one who killed Dick Roman, the one who killed Cain, the one who killed Death. And he’ll kill God and his fucking sister too before he lets Sam anywhere near the Cage.
“How’d you sleep?” He asks in the morning, aiming for casual but not quite pulling it off, if Sam’s suspicious frown is anything to go by.
“Uh, great. Like a baby.”
Now it’s Dean’s turn to give Sam a suspicious look, letting his gaze slide over Sam’s slumped posture, the pale skin, the circles under his eyes. “Really. So you’re not scared shitless by the prospect of going back down there?”
Sam flinches, then freezes for a second before letting out a long, carefully controlled breath. “But you said yesterday – “
“I know I said no, Sam,” Dean interrupts. “But honestly, when has that ever stopped you? Besides, I know what you look like when you’re thinking about doing something noble, self-sacrificial and colossally stupid.”
Sam nods, accepting the accusation. “Look, I’m not saying I want to do it,” he laughs shakily, six foot five and so scared and so fucking brave, “But… What if there’s no other way to beat the Darkness?”
“We’re gonna find one, okay? We’ll figure it out, just like we always do.” The last time Dean heard this mantra, it was Sam saying it to him, and Dean didn’t believe it but he should have, should have remembered the power of a Winchester on a mission. “And I think I know where to look for our first clue.”
That catches Sam’s attention. “Yeah? What is it?”
“What’s that supposed to mean?”
While Sam’s eyes burn question marks into the back of his head, Dean turns to the counter to pour two cups of coffee, dropping two sugars into one and handing it to Sam. “Wanna sit down? I think I’ve got some explaining to do.”