It's the smell that throws him. Not the lacerated skin on his palms that knits back together within hours. Not the way the light hurts his eyes. Not even the hunger gnawing at his belly. It's the smell. The smell of Dean's blood. The scent of family, of home. Sam's whole world.
Gordon's "one last good thing". Blood on the wire. The gift that keeps on giving.
Sam crawls silently onto the mattress, nudging his nose against Dean's jaw while Dean sleeps. Dean murmurs and sighs, frowning, lost in dreams. Sam lingers, inhaling deeply. Fingertip to Dean's pulse, he smiles.
Dean wakes up slowly. Sam doesn't rush him. He wants to give Dean his moment of realisation, allow him that much dignity.
Dean realises almost straight away, jolts and strains against him, but Sam doesn't let up, using his new strength to pin Dean to the bed so easily it's exhilarating.
Sam had fully expected Dean to lose it completely, to struggle against him in a berserker rage. Instead Dean closes his eyes, fat tears sliding back into his hair, and offers Sam his throat. Sam hates that Dean surrenders so easily. Hates it.
It doesn't stop him from biting.
The stillness is too much. Sam paces, moving the air around, craving an end to the interminable waiting. It's taking too long. Maybe he made a mistake. He can't be sure. Didn't know what he was doing, not really. He knows the lore, but theory and practice are two very different things.
He didn't have a choice. He couldn't have let Dean go without tasting him, without drinking him down, overwhelming and alive.
Part of him, the part that's still human, wonders if Dean dies tonight, was it worth it? Worth that fleeting taste, ephemeral and forever on his tongue.
Dean opens his eyes and sits up like he's hinged at the waist, gulping in air like a drowning man. Sam's across the room in a heartbeat, straddling his brother's thighs, all propriety forgotten, touching Dean everywhere. Dean just sits there, dumbstruck and wide-eyed, letting Sam manhandle him.
"Sam?" comes out small, hesitant.
"Dean." Sam says it low and thankful, a benediction. Relief burns his throat, fills his chest. He rests his smile against Dean's throat, bites down on that same spot. Doesn't break the skin, but nips hard enough to bruise.
A gentle reminder about who's the eldest now.
"You think this is easy for me?" Dean asks.
Sam surveys the room. Broken bodies, torn throats, blood everywhere. Dean's calling card. This is what happens when he can't control the hunger.
Dean stands alone; a pale statue clad in blood and old denim.
"Why'd you do this to me?" Dean asks, soft and curious, like he really needs to know.
"Because..." Sam shoves his hands in his pockets. "I didn't want to do it alone."
"Okay, Sammy, okay." Dean pulls it together enough to smile, sharp and brittle. "Well, I'm full. How about we get you something to eat, huh?"
It's different now when they fuck. Dean's storm clouds still gather -- guilt, Sam supposes, although he doesn't get it, he's long since corrupted, long past caring -- but Dean's not afraid to touch anymore. Not afraid to initiate, to croon filth into Sam's ear while he fucks into him from behind, licking sweat off the broad curve of Sam's shoulder.
And sometimes, sometimes he even bites, and those are the best times. Then it's just the two of them, smeared with blood, snarling at each other through awkward fangs, laughing at how they look, amazed at what they've become.
"You have to be more careful."
Dean's laughter echoes around the church's rafters, loud, no fear of reprisal. "What for? We're unstoppable, Sammy."
"You don't know that. They could still come."
"So? We can handle a few hunters."
Same old recycled argument. It's not hunters Sam worries about and they both know it. He knows Dean misunderstands on purpose -- some things never change.
Dean leans in, fists Sam's shirt, a challenge Sam can't resist. He licks Dean's jaw, slick with blood, none of it Dean's.
"Just be more careful."
Dean grins, feral in the half-light. "Always, little brother. Always."
They come for Dean in daylight, making it harder to run.
Months spent running, chasing the distant horizon. Sam's endless quest to break Dean's deal. Dean sidetracking him at every opportunity: luring meals, "just for kicks" hunts, bar brawls, the Grand Canyon.
Infinite distraction. A life lived.
Now Dean lies drenched in his own blood, hell-hounds circling. Sam's hands flutter uselessly, trying to hold him together.
"Stay with me."
Dean grins through the pain. "No sense in fighting it, Sammy. Not your call. Vampires don't get to go towards the light."
Sam sobs and breaks open.
The hell-hounds edge closer.