Warnings: Slightly abusive, excessively unhealthy relationship. Mentions and suggestions of sex.
AN: For Teddy.

I.

He's got plans upon plans. A Ministry career, just like Crouch Sr.

"Something with magical law enforcement," he says mechanically. "Then, after that, maybe I'll work my way to Minister."

But you hear through Barty's false pride in all the hopes and dreams of what he will do, of what the future will hold. Those aren't his dreams. Those are ideas planted into his head by years of careful grooming by his bastard father.

And you see the darkness in his eyes. Barty only wants to escape. He's so easy, so eager, and you know it will only be a matter of time.

II.

"Do you really want to live in your father's shadow?"

You delight in the way Barty tenses, the way he quickly turns his attention to his book as though the things on the pages can make you disappear.

"I don't think you do," you continue, giving a shark-toothed grin and snatching the book away, forcing Barty to look at you.

"I'm not supposed to talk to people like you," Barty says dryly, reaching for the book that's just out of his grasp. "Father says it's hazardous to my future."

You tuck the book behind your back. You'll hold Barty's attention, even if it's by force. "And you're such good boy, aren't you, Crouch? Always doing what Daddy tells you to, I'd wager."

The red that flushes over his cheeks is satisfying. "Piss off, Black."

You lean in dangerously close. You know the effect you can have on people, male or female. Not that you really want anyone. It's just a game, worming your way in, using your natural charm as a weapon, a means to an end.

Your lips graze Barty's cheek, not quite a kiss but packed with the illusion of intimacy. Barty inhales sharply, and you whisper in his ear. "I can save you from becoming your father. I can help you become so much more."

With that, you drop the book onto the table and walk off, letting your words sink in and find home.

III.

It takes Barty a week to seek you out. Seven days exactly, and he walks up to you, all shifting eyes and trembling hands. "How can you help me?"

Inside, you are silently gloating over your little victory. Barty Crouch Jr., the awkward little good boy with his nose permanently pressed in a book, has given into you so easily.

You don't even glance up at him. A smile twists your lips, proud and triumphant. "Are you sure you want to know? What will Daddy Dearest think?"

"I don't care."

Now, you do look up, smile shifting into a grin. "You just have to do one thing."

"What's that?"

"Burn with me."

IV.

You grab Barty roughly by the hair, aiming to hurt him as you pull the older boy backwards. "You have to mean it!" you snap. "The Dark Lord doesn't want cowards!"

Tears in his eyes, Barty shrinks back. "I'm trying!"

"Merlin, you're worthless," you say with a glare. "May as well run back to Daddy like a good boy."

Something inside Barty snaps at the taunt. He aims his wand at the bound first year, pale eyes wild. "Crucio!"

The girl writhes, mouth opening in a silent scream.

"Crucio!"

You fold your arms over your chest, smiling to yourself. Barty is such a fun little toy. Press the right spots, and he'll do anything.

"Avad-"

You grab his wrist in a bruising grip, jerking his arm roughly. "Don't be stupid!" you snap before aiming your own wand at the girl.

Torture is easy enough to hide. But murder?

"Obliviate," you say, and the girl's pained expression grows blank.

Realization seems to hit, and Barty hunches over, dry heaving from the shock.

You roll your eyes. "You've got a long way to go."

V.

The night before you leave Hogwarts for good, the two of you sit atop the Astronomy Tower.

"I'm scared," Barty admits, looking at you with those poor, lost puppy eyes.

"You should feel honored."

"Will it hurt?"

Silence.

"I don't know if I can do it, Regulus. I-"

You kiss him, not because you want to ease his fears, but because you want desperately to shut him up. Your fingers grip Barty's chin, leaving little bruises in their wake as your free hand tangles in Barty's hair.

With a sound somewhere between a whimper and a moan, Barty parts his lips.

You want to laugh. Too can do anything to Barty, and Barty, so faithful and adoring will just take it without protest.

Barty pulls away, gasping for breath. "I'm sorry," he murmurs. "You're right. I should be proud. I-"

"Shut up," you groan, pulling him in for another silencing kiss.

VI.

Barty holds your hand as the two of you are Marked. You feel your bones grinding together, but you let Barty squeeze through the pain.

And then it's over. You're Marked, a skull and serpent burned into your skin, binding you together with a commom cause.

"It's over," Barty sighs, relieved.

You laugh. "No. It's only just begun."

VII.

Somehow, you spend most nights in Barty's bed. Even if you don't care for Barty, you enjoy the little perks that come with his devotion.

The two of you lay together, tangled in bedsheets, slick skin upon slick skin. You bite the back of Barty's neck, enjoying the visible tremor that shoots down the older boy's spine. So eager, even if you are a selfish lover who only takes and takes and takes everything Barty has to give and more.

"I love you," Barty whispers.

You freeze, climbing off of Barty, eyes wide.

Love?

You suppose you should say it back. Even if it's a lie, it's the least you can do after everything Barty has given you.

But you can't, and, somehow, Barty doesn't seem to mind.

VIII.

The change is subtle. At Hogwarts, you had seen only a glimmer of darkness in Barty's eyes, just a spark.

Now, that darkness is always there.

Barty is changing. Barty is slipping.

You tell yourself that you shouldn't care, but you do.

IX.

"Barty?"

"Yes, Regulus?"

He still looks at you with those puppy eyes, like you can guide him home. At least that much hasn't changed.

You shake your head. "Just checking," you say before kissing Barty, more teeth than tongue.

X.

Barty is proud. "She was begging for mercy, Reg. You should've been there."

Secretly, you are grateful you'd had other plans that night, but you don't mention it. "You've changed," you say, remembering the way Barty had doubled over, desperately trying to keep his breakfast down after your first victim together at Hogwarts.

Barty doesn't seem to notice the accusation in your words. He just beams, nodding. "Isn't it great?"

You force a smile.

Shouldn't care, you remind yourself. But it's like arguing with a brick wall.

"Yeah, Barty. Great."

XI.

You two fall into bed again. Nothing new. You've done it time and time again.

But now, Barty fights for dominance. Now, he's not just satisfied to be lead along.

His nails dig into your back, scratching little lines of fire into your flesh as he tries to force you onto your stomach. You suck in a shocked breath, eyes dark as you look down at him.

The other changes, you can accept. But this... Letting him take control. You can't, can't, can't

Knuckles cracking into his cheek, you quietly remind him that he is yours and not the other way around.

And Barty accepts it, though not as easily as he once had. Grumbling and looking at you through narrowed eyes, he gives in.

XII.

You feel sick when Barty comes in, covered in blood. God, when did the tables reverse? When did Barty become the cold, indifferent one? When did you become so weak, so concerned?

"Barty?"

He swaggers closer, gripping your face with blood-slick hands. You barely have time to register the warm blood painted across your flesh before he captures you in a deep, forceful kiss. "Miss me?" he asks with a smirk, offering no explanation to calm your mind.

You wipe your hand over your face, pale knuckles coming back crimson.

"Yeah," you answer with a shaky smile.

It isn't quite the truth. You miss the old Barty. Not this.

And something sinks in your stomach, twisting your organs into knots. Something bitter. Something acidic. Something that eats away at you, that you can't quite name.

XIII.

You're fading. He's growing brighter, more sure of himself, and you're burning out, plagued by questions and doubts and fears.

He's becoming a monster, and you know that you're to blame. You've groomed him. You've flooded his veins with your desires, with your fun little game.

He is the monster you've made him.

XIV.

You give in to him. You've changed him into this dark creature, and it's the least you can do.

Barty isn't gentle. Perhaps he might have been once, back when he'd still been human. But now he fucks into you, tearing you apart, thrusting hard like he's trying pound something into your head.

And, as he collapses on top of you, sucking little bruises over your chest, his message is crystal clear. He is broken, twisted, wrong, and it's by your hands. Now, he's going to break you too.

XV.

You know you have no choice anymore. Things aren't how you'd planned them long ago.

You'd had dreams once. Dreams of joining the Dark Lord and making your family proud. Dreams of claiming Barty as your own, of twisting him into your fantasy.

But that's gone now. Your beautiful dreams have spiralled downward into the realms of nightmares.

The Dark Lord is not what you've believed him to be. Barty is no longer the puppet whose strings you can pull.

Those days are gone, but maybe, just maybe, you can fix things before they derail completely.

XVI.

You've found a way out. There's a light at the end of the tunnel, and maybe you can reach it time. Maybe you can repair your mistakes.

The Dark Lord has a weakness.

Barty might not be too far gone yet.

You're burning out, but you know that stars explode into one last burst of light before the end sets in.

This can be your supernova.

XVII.

Barty is drunk and grinning at you with twisted lips. He grabs your wrists, forcing a bruising kiss to your mouth.

"I have to go," you whisper weakly. "I told my parents I would be home tonight."

Barty laughs, pulling back and patting your cheek roughly. "And you always do what you're told, don't you, Regulus? Such a good boy."

Before you can answer, he has you pinned to the wall, crushing lips capturing yours again. His hands grip your hips, thumbs hooking into you trousers.

This isn't how you'd planned it. But maybe it's the only way you can say goodbye.

Eyes closing, you go slack, giving in to him once again.

XVIII.

He's slumped on the bed, eyes closed, chest rising and falling slowly as his breathing finally levels out in sleep. Now he looks peaceful. Now you can almost believe he's still that innocent seventeen year old looking to you to guide him.

Of course, those days are gone. You know what dark dreams flicker behind his lids. You're the one who had put them there after all.

But you can pretend he's still your Barty.

You sit up, the sheets draping your sweat-damp body. Trembling fingertips caress his cheek.

Your fault. All your fault.

"I'm sorry," you whisper. "I love you. I'll set you free."

With that, you pull on your clothes, and then you're gone.

XIX.

"Master Regulus is late," the elf says.

You can tell from his tone that he'd hoped you had changed your mind, that you wouldn't order his return to that cave. You almost wish he could be right. Wouldn't it be easier to just accept that everything has changed? Wouldn't it be easier to let Barty be the monster that you can't let go of?

Of course it would, but that is not an option anymore.

"Come," you say, trying not to betray your fear. "We've work to do."

XX.

Down, down, down you go, water flooding your lungs. Maybe you should be afraid, but you're at peace.

You've defied the Dark Lord. You've broken your chains.

Maybe your sacrifice can do the same for Barty.