Sam dreams about Jess – yes, he does, all the fucking time, and he can see the flames engulf his girlfriend, her slicked mouth wide open, terror in her eyes – and it hurts. Of course it does. It hurt the days before she died, and it hurt more – harder – the days following.

But her nightmares (he feels guilty and ashamed for thinking it) are not the worst.

The worst ones are always about John.

His dad.

They're not blood-curdling, shudder-wracking dreams (they barely classify as nightmares) but they feel real. Realer than Jess, realer than heat on his face from the fire. They're dreams about the Stanford fight, the big, huge, ripped-a-hole-in-Sam's chest Stanford fight. He still remembers standing on the porch, dressed in jeans and plaid, duffle bag clenched in his left hand.

"Don't come back," his father said, eyes deep and dark like a demon. "I don't want you stepping into this house, not after what you've done.

"But – I –"

"That's enough. You made your decision, didn't you?"

He didn't want it to end like this. He didn't want to end it with John's stark naked gaze, the flurry of disappointment and wrath in his eyes. Sam didn't want to remember the look on his father's face; this stony, impenetrable wall – newly formed. He stepped forward, swallowing the bile down his throat.

"I'm sorry," he said. "I've got to do this. But we can still-"

His words sounded shallow and stupid even to his own ears. He was leaving his family, the people that had raised him, for an easier life. Sam felt a curl of shame in his stomach, and even as it clawed – biting at his intestine – it didn't change his mind. He was selfish. He knew he was. But it was the kind of selfishness that he couldn't reverse.

"It's just a few years," Sam finally said, fumbling around his words.

"It may be a few years for you," John said, words sharp. "But it's a lifetime for me, Sam. You walk out that door, and it's a lifetime."

He walked out the door anyway, felt the swath of cold air on his cheek, the end of an old chapter. He made the mistake of looking back – just for a glimpse. John stood at the entrance, staring at him with poison eyes, distance and bloodline separating the killer from the prey. Sam swallowed down the fear – shook his floppy, overgrown hair out his face – and started toward the bus stop.

But that last look was imprinted in his mind, an inked tattoo burning under the skin of his skull, waiting to jump out at him in the dark.

.

"Sam. Sam! Dammit, Sammy."

"No," Sam mumbles, rolling and twisting under tangled sheets. "I didn't mean to, I'm sorry – I'm so sorry."

Dean chucks a pillow at Sam, hoping to snap him out of whatever hellish dream he's having, but it has no effect. Sam continues to writhe against the bed sheets, brown hair plastered to his forehead, lips parted open. He talks in his sleep – begs – "I'm sorry, please let me back in, please let me in," and the words are painful to listen to.

It's only been a week since the fire with Jessica, and only a week since they've started hunting together. Sam's been gone so long in college that Dean's forgotten what it feels like to care for him. He's forgotten how much Sam means to him. But now it's coming back – the big brother instinct - fast and hard – and it punctures him in the gut.

"Sam," Dean orders. "Wake up."

Sam doesn't. He kicks at the sheets. "Open the door! Open the door!"

"There's no goddamn door," Dean grumbles, and he reaches forward, grabs Sam's bicep with his hand.

Sam freezes at the touch. His sweaty brow furrows. "De…"

Dean swallows the lump in his throat, because even after four years, even in the middle of a nightmare, Sam recognizes him.

"Wake up," Dean whispers.

Sam is still as a sedimentary bone, caught between nightmare and reality. Then Sam's eyes flutter open, sweat gliding across his flushed face, his stare painfully and deeply hurt. Dean hovers above him, over the bed, relieved but uncertain.

"What…" Sam clears his throat. "What happened?"

"You were…dreaming," Dean says. He lets go of Sam's arm, and straightens up.

"I was…" Sam closes his eyes. "Right. Sorry."

"What was it about?" Dean ventures, wanting to demand answers, yet shy away from them at the same time. Sam stares up at him, cheekbones hollow, lackluster light in his eyes. He chews on his wet lower lip, trying to figure out an appropriate answer, and Dean can see the wheels turning in his head.

The excuses.

It was just… nothing. No big deal.

This job really gets to you, you know?

The fire.

Dean doesn't want to hear excuses. He wants to hear Sam trust him again.

He touches Sam's shoulder – brief contact with his knuckle – and hopes it's enough to make Sam spill.

It is. Sam trembles, and clenches his left hand around the fabric of his sweatpant-clad thigh. "It was about dad."

The word dad stops Dean cold. Dad? How could it be about dad? Dad doesn't bring nightmares. Dad brings safety and comfort and warmth. Dad doesn't make anyone squirm in their sleep, buck and kick and look miserable. Dad doesn't make people tremble the way Sam is trembling, tremors snaking up and down his spine.

It's too dark, and Dean's throat is dry. "What?" he manages.

"It was… I know… I'm sorry." The disjointed words come out hurriedly. Sam's hand clenches tighter, digging into his thigh, and Dean thinks, that's going to leave a bruise but he can't voice his concern. But then Sam's words come back to him – the mumbling during the dream – and it hits Dean that Sam's dreaming about the fight.

The fight that had torn their family apart.

Let me back in, please let me back in. Open the door!

Dean's words catch in his throat, and the lump is inescapable this time. He breathes in sharply as if his esophagus has been scalded; burned to pieces. Because Sammy was begging to be let back into the house, back into his family, back into loving arms – and Dean can imagine his father, twisted into an ugly version of his worst, slamming the door, again, and again.

And yeah, Dean can see how that would be scary.

He sits down next to Sam, presses their sides flush together, and wraps an arm around Sam's frame. Sam shakes.

"Dean…"

"He's not pissed, okay? He's not."

"He hates me." Sam's eyes are glossy, and fuck, Dean feels like a piece of shit. And Sam digs his nails harder, and harder, and Dean fears he'll draw blood. Throat still sore with the pressure of holding back tears, Dean encircles Sam's body, all the way around, and holds him close, like when they were little.

Like when they were little, Sam curled up against his chest, dimpled grin on his cheeks as Dean read him his favorite book, The Hungry Caterpillar.

But this time they're not reading about a ravenous caterpillar. They're 22 and 26, separated by the wall of time, and Dean presses Sam closer, cards a hand through his baby brother's hair. Prays and wishes that Sam will stop shaking.

Sam lets out a choked sob. Whispers: "Promise?"

Dean struggles to understand. Then he gets it.

Promise dad's not pissed at me? Promise he'll open the door and let me in?

And Dean's supposed to fix things – it's always been his job, always will be – so he closes his eyes, clenches Sammy tighter, and says: "Promise."

And Sam starts fucking shaking again, crying harder, and Dean panics oh no, what the fuck did I mess up this time, I'm a worthless big brother, I'm a worthless person until Sam grips his shirt, loosens his nails, and Dean realizes it's relief. His brother is shaking from relief, four years of pent up emotion dripping out of his body.

"Dean," he mumbles, over and over again, "Dean, Dean, Dean."

It's scary how much he clings – how much he depends on Dean to make everything better. It's scary because it means Dean is carrying the weight of the world on his shoulders, because Sam is his world, his world of dimpled-grins and bright-eyed geeks.

But Dean knows that no matter what comes forth (not knowing about the demons, John's death, the hell, the blood, the possession, Lucifer, betrayal, the Mark of Cain) that he will ignore the ache in his shoulder blades, the sting in his back, and carry Sam to the finish line.

Always.