The world is a blur that shifts between powder-blue and white-gold.

And then, suddenly, it's red. It's all red.

The second Castiel disappears, a stitch in Sam's chest loosens. Adrenaline and love for his brother brought him this far; but with one of those factors missing, the equation unbalances. Sam tips with it, seeing smears of crimson stars, whole galaxies that look like fire and smell like searing flesh.

He hits the floor, the shards of glass from his broken wall no no that's not right the wall was never glass it was just smoke and mirrors mirrors are glass it was plaster it was him it was weak from something Castiel broke, or Dean broke, jabbing into his hand. There's heat and wet on his face and tears gathering in the corners of his eyes.

The whole world shrinks into pain, everything else eclipsed; fire races and burns across his arms, chews its way through his hair, slides into his belly. Meat hooks and knife points and teeth stripping the skin from his bones.

Sam collapses onto his shoulder, his limbs twitching feebly, unable to escape the fire, so why try? He's done what he could—couldn't stop Castiel, couldn't stop any of it, too late—and why get up again? He's lesser, he's second-best, he wants to stay down and stay under and never rise again.

And then, suddenly, the heat is moving.

Not inside of him, not devouring. It's outside, but it's underneath.

It's shaped like rescue and it feels like comfort. Over his chest, over his thready heartbeat. Something that feels a part of him, even removed.

A voice stretches across the flaming chasm. S—m. S'm?

And then, that word he missed so much: "Sammy?"

He gasps, a wildfire burst of blessed air. The hand on his chest rubs a furious circle, stimulating his pulse like nothing he's felt before. "Easy, easy. Just breathe, Sammy, I'm right here."

Sam's hand searches, and finds a bloodstained sleeve. His voice is a hideous rasp to his own ears, sandpaper on steel. "Your arm."

"Don't worry about my friggin' arm, your head's in pieces."

Sam doesn't doubt it. But there's a kiss of comfort, a swell of relief stronger than adrenaline. "You didn't."

"I didn't—what?"

"Lose me." Sam blinks open gummy eyes, and the powder-blue, white-gold fades to let in a haggard, anguished face. So much guilt and so much pain. "M'right here, Dean. It's okay. I'm not gonna leave you alone."

Dean's free hand, his uninjured one, doesn't seem to know what to do with itself. It cups the side of Sam's neck and slides down the tense arch of his shoulder and finally knots itself in his collar, giving him the smallest of shakes. "That's my line, bitch."

With Dean's arm to anchor him, Sam hauls himself up and buries his face in his brother's chest, the smell of whiskey from Dean's pores and the leather from his jacket canceling blood and pain and fire, at least for now.

Dean's hand abandons his chest and threads into the hair on the back of Sam's head, and they could be collapsed on a muddy street rather than a mildewed warehouse and Sam could be dying all over again, and still, always, he'd come back for this.

"We better shag ass," Bobby says. "Think you boys can walk?"

Sam nods against the side of his brother's neck, and tries to help, he does, when Dean rises; but he feels like he's misplaced his feet and he's walking on hot coals, through twisting miles of burning asphalt, and it takes Dean on one side and Bobby on the other to make him vertical. Dean keeps one arm around Sam's back and retrieves his gun and follows Bobby. And Sam, blindly, follows Dean.

They make it outside but they're not going back to the Impala and Sam slows his stride when he thinks, why, where is she? before he remembers passing her on the way in. But luckily there is a car, or a van rather, it's a two-seater parked under the trees nearby and Sam has a second to dread being locked in the Cage separated from everyone in the cavernous back before Dean says curtly to Bobby, "You drive."

He pulls open the back door and gives Sam a nudge to get him inside, and then he slides in too and closes the door. And Sam sits with his shoulder to the seatback and his knees halfway up to his chest and he wishes he could curl up and hide and disappear.

But then Dean's there. Dean's arm is draped across the back of Sam's neck and he pulls Sam over, resting his forehead against Sam's hollow temple. They don't say anything, anything at all, as Bobby peels out and drives like a madman away from the place where everything old ended and everything new began.

And maybe, in the silence, they say everything.

Sam thinks fuzzily for a second, Dean is going to kill me, before he lets himself fall asleep, his overgrown body listing heavily against his brother's shoulder.

So Sam doesn't feel Dean's free arm wrap around his front, or his brother's hopeless, heartbroken and miserable tears spangling across his arm.

Something had changed; in a new world forged of tears and souls and fire, they were going to have to rediscover each other. But they had miles to go before Bobby's house, and that was miles of a solitary world of powder-blue, white-gold, blood-red and pitchblack.

And the first thing Dean would do when they had Sam in a real bed, rallying from the damage Castiel had done, was bind the puncture on his hand, and remind him that he was home.