Prompt: Jim kidnaps John, Mycroft and whoever else you please (Lestrade, Mrs Hudson, Molly etc totally up to you) and forces Sherlock to choose only one of them to survive. I only have one condition, Sherlock must choose Mycroft. Anything after that is up to you, happy ending (as in someone rescues them in time), dark ending, bittersweet etc. I don't mind it all, I just want Sherlock to choose Mycroft with everyone as the witness (perhaps Sherlock is as much a 'prisoner' as everyone else). Not really fussy, just want to have Sherlock choose his brother over John for once.

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Jim is laughing when they push him inside.

He gets out of the cab at Trafalgar Square and sees Trina, one of his homeless network, motioning to him desperately from across the road. Before he can react, he's grabbed, chloroformed, and shoved in the back of a sleek black car. He comes to being dragged, hands gripping him roughly under the arms, and he fights back for a moment before one of the men threatens to drug him again. You'll want to be awake for this, he points out, and Sherlock takes the hint. They let him walk the rest of the way, but they push him through the door, and he feels the gun press between his shoulder blades.

"What's the meaning of this?" Sherlock asks, but he knows. He doesn't look around the room – can't look yet – keeps his eyes on Jim, on his eyes, on the frantic pleasure there.

"You know why you're here, Sherlock Holmes," he murmurs, leaning too close. Moriarty's always too close. "Three people, you choose who lives and who dies."

"If I refuse?" It wasn't an option. He's grasping at straws. Anything to stall until someone realizes they're all missing.

"Then you can all die…" Jim smiles as he says it, wide and frightening.

"Choose, Sherlock."

There's a noise behind Jim, and Sherlock has to look.

Molly had dropped to her knees. Tears stream unchecked down her cheeks, but she's silent, eyes wide with fear and fixed on a point beyond him. The door, he thinks, and he watches as John kneels beside her – slowly, and the gun pointed at his head follows him down – and takes her hand. But John is watching Moriarty, his expression stoic and fixed. Nothing betrays his emotions but the white-knuckle grip he now has on Molly's fragile hand.

Mycroft stands beside them, leaning slightly on his umbrella. He is impassive. Never has Sherlock wished more strongly that he could read his brother.

"Who will you pick? Oh, this will be hard for you, won't it, Sherlock? Yes it will, who will you—"

"Mycroft."

Jim blinks at him, a train derailed, trapped in the middle of his sentence.

"My brother, Moriarty, let him go." He tries to sound forceful, not desperate, not broken.

Molly sobs then, letting go of John's hand to cover her face. She knew he wouldn't pick her, that was never a question, but igod, to die this way./i John closes his eyes and puts his arm around her shoulder instead, and finds he can accept this. He thinks of Harry, and knows he would never have been able to look at Sherlock the same way again, if the man had chosen either of them over his own brother.

Sherlock can see the shock on Mycroft's face, and he takes back all the times he's ever wished to know what his brother was thinking.

But Jim starts smiling again, a deaths-head grin, reaching out as if he might touch Sherlock – brush away that stray curl, touch his cheek, his lips – and Sherlock frowns.

"Sebastian?" Moriarty calls, and the man whose gun is pointed calmly at the back of Mycroft's head shifts his weight. "Shoot him," he whispers, hand still outstretched towards Sherlock, and the man cocks the hammer back.

Blue eyes go wide and fear almost betrays him. "Wait, Jim—"

The madman grins at him. "I never said the one you picked would live."

Sherlock dove at Moriarty, catching him by the neck, and they both went down as the shot rang out.

Someone is running. Someone is shouting, police are pouring in the room. Tendrils of black are crawling around the edges of his vision. A woman is crying, heavy, loud sobs. A gentle hand takes his pulse. Someone is calling his name. Someone.

When he wakes, the sky is white and cold and his hands feel empty.

"Moriarty got away," Mycroft says conversationally. His eyes are bloodshot and tired, he's pale and shaking.

Sherlock frowns at him, and then his hands aren't empty because Mycroft is holding one, tightly.

"You're going to be alright, Sherlock."

"…unnecessary to reassure me. Of course I'll be alright. And you're safe."

Mycroft smiles the smile Sherlock remembers from their childhood, and all the tension goes away.