Warnings: lack of agency, abuse, violence and dark themes.
Summary: Remember that powder that Magnus had, that could control people? What if Dean decided to use it on Sam, pushed by the Mark's dictatorship? What if it gets out of control?
Sam loved Dean more than pretty much anything else. It was a fact he’d come to accept after Dean died and went to Hell; Dean was his family, and it is what it is, a floundering, overwhelming connection. Ever since Magnus tried to keep Dean as a pet, Dean’s been easier to be with. Things are just… simpler. Dean jumps, Sam jumps with him. Dean needs something, Sam is more than willing to do whatever needs to be done. Because Dean’s word, it’s something… important. It’s always been important. It’s more than that, now, though; it’s a need. Sam… he needs to know what to do. He feels physically and mentally starved for it.
It’s harmless little commands at first. There’s a hunt a few miles out – a vamp’s nest. Dean tells Sam not to leave the bunker, voice stern, and Sam sits down at the table with a nod. “Sure thing, Dean.”
“… No, Sam, come on. I’ll need back up.”
Sam rises to his feet without complaint. Dean rubs a heavy palm over his chin, quiet for a moment. There’s something reflecting in his eyes, a kind of darkness swirling there caused by the taint of the Mark, starkly pink on his flesh. “Magnus’ powder worked… Just needed a little tweaking, but…”
“Hm?” Sam asks casually, packing his laptop up.
Dean plans the hunts, and the hunts go well. Sam never says a word to it, and even if he tries, it simply takes a single command for the overgrown hunter to shut down, tuck tail and sit still, quiet, obedient. This is for the best, though. Somewhere in Sam’s still functioning mind, he wants to scream, wants to fight it. With every disapproving wrinkle of his brow, there’s Dean’s voice shutting him down. But then, he deserves it, doesn’t he? He always needed a chaperone; he always makes bad choices; he always ruins things.
“Keep your thoughts to yourself; this is for your own good, Sammy,” Dean says one night, the veins around the Mark a purple-pink that ripples and slithers. Dean’s drank too much, his alcoholism always there in the foreground enough that Sam’s tongue struggles, thick, against the roof of his mouth. Stop drinking so much, Dean, you’ll kill yourself, and then who will tell me what to be?? What to do? “Stop trying to grab my drink.” He stops. “You don’t get it, do you? This is how I keep us ready. All I have to do is tell you to walk away and forget about me, and you’d do that. Get it? It’s for protection.”
Sam screams and screams and screams, all voiceless and unheard, mouth shut.
The Mark gets worse. Always worse. Dean commands Sam to hold a shifter still while he buries the blade in the monster’s spine. “This is for your own good,” Dean says, high off of something Sam can’t comprehend. But he’s probably right. It’s probably important. Dean is always right, isn’t he? He stares down at the hair interwoven in Dean’s hand from the corpse, blood-spackled and twisted. “Don’t say a word, Sam. Not a word.”
When he tries to leave the bunker in the middle of the night, Dean commands him into a room beside his.
And then… Dean dies, and becomes a demon.
It would have been easy for Dean to have walked away, if Sam weren’t a compliant plaything. It would have been. Sam has faith in his brother that he would have walked away if he could; it’s all he can think to keep even a fraction of his sanity now. His brother snaps his fingers, eyes onyx, a milky black that floods his eyes. The bar is rundown, Dean sitting in one of the old chairs and ushering Sam with his words. Sam obeys, getting on his hands and knees so that Dean can put his feet on Sam’s back to rest them.
Crowley’s eyebrows raise, and even he is caught off guard. Startled by the sight. “Fancy training, I see.”
“It’s fantastic. No wonder Sammy’s wanted a dog for so long.” Dean reaches down and pats Sam’s shoulder, and Sam craves the old Dean enough to pretend it was truly his brother reaching out to him. He closes his eyes as Dean continues, “Got it all down. Even had him cut his own tongue out so that he’d stop trying to throw the touchy-feely crap at me.”
Three years, and Sam listens. He kills when asked, he stands alone in the dark and waits, he prays silently in his head.
Castiel eventually hears his prayers and finds him sitting cross-legged in an old abandoned apartment complex, while he’s waiting for Dean. His hair is unkempt and his clothes wrinkled, eyes dully lit. “Oh, Sam,” Cas says, voice soft. He puts a hand on Sam’s shoulder, and god help him, Sam just wants to melt into the warm touch.
The angel uses what he can of his depleting wilted grace to fix Sam’s tongue, but the man never says a word. Not when Castiel cures Dean, not when Dean’s eyes melt from that inky black into the green he’s familiar with. Doesn’t speak when Castiel tells him it’s done. Sam simply sits, forehead on his knees, back against a wall. Dean’s shadow falls over him – terrifying and relieving all at once, as Castiel speaks, voice almost leveled and free of righteous judgment, of anger (but not quite, not quite). “I fixed his tongue, but I can’t remove the spell you put on him.”
“Sammy,” Dean’s teary voice cracks – for the first time since the spell. “Sammy, I’m so sorry. I don’t know what happened… I don’t…”
“Don’t,” Sam rasps, his own throat thick with emotion, arms tightening around his legs. “Don’t say anything.”
And Dean obeys, letting the silence trickle in.
Sam looks up, smile forced and heavy and twisted, and asks, “What do I do now?”
Dean rushes out of the room, leaving Castiel, fists clenched, and Sam, unsure of who he needs to be.