"What did she mean?" Sherlock asked, his brows furrowed. He spoke in a hushed tone, though there was a definite edge. "What did she mean about calling you? You said they sent a tape of her-" he stopped himself then, looking away. There was a look of disgust on his face.
"They did, of sorts, but that was after- She had called before, she told me they had taken her and what they wanted for her freedom-"
"Then why didn't you give it to them? She's your sister, for god's sake. You nearly got her killed, put her through unspeakable torment. Do you enjoy the pain of others Mycroft?" he snarled.
"I did everything I could, but my hands were tied. Whetherby wouldn't budge-"
"So you left her to die? Are all of your government secrets worth it?"
"That's easy for you to say, Sherlock! You have no idea the millions of lives that information holds. You have no idea what it's like to deal entirely in secrets surrounded only by liars."
"Stop. Just stop."
They turned. Isla stood in the doorway, her hair mussed, eyes red from crying. It had been hours since she'd awoken from her drug induced stupor. Sherlock had sat with her for much of it, silent, listening as she told him where she'd gone and what had happened in Yemen. She didn't tell Mycroft any of this, but he listened out of sight all the same. She'd visited the boy's grave she said, and she spoke in such a timid, almost petrified voice that it was alarming.
"Sherlock, I didn't feel anything. It's like he never existed. I can't wrap my head around it, but since I came back I don't feel like myself. I don't even feel bad about those men I killed-"
"Why should you Isles?" Sherlock asked, smoothing her hair back from her face. Mycroft had noticed these little things, the way he would reassure himself that she was still here. A hand on her shoulder, or a brush of her face, anything to prove that he wasn't imagining it. "They were going to kill you. I mean, look what they did to you. You nearly died."
"But Sherlock- I really loved Alfie. I mean, I think I did. But now…" she trailed off, her shoulders slumping. "Sherlock, all I can think about are those men."
"It's ok to be frightened-"
"No, Sherlock. I want to kill them. All of them. All of the rotten, loathsome people who ruin people's lives."
"Isla."
"I was going to work in a museum, Sherlock. I was going to get married and be boring and the whole lot. Then I was going to die. But since that man came and helped me get away- Sherlock, I'm not anything anymore."
"Mye, you haven't called anyone? No one knows I'm here?"
"How could I, with your little-" he stopped himself at a look from Sherlock. "No."
"Fine then, good. You need someone who you can trust, who won't screw you over, right? That's what happened in Yemen. So now, you'll have me. It's perfect. No one needs to know I exist except you and Sherlock and Mum and Dad and I can train in MI-6 under a fake name. You can sort everything out."
"No, absolutely not," Mycroft said quickly.
"That's crazy Isles," Sherlock said at the same time.
"No its not, and you both know it. What do you expect me to do, go back to school? I can't. Not when I know what kind of people there are out there and how much damage they can do. And I need to find-" she broke off, her mouth snapping shut. But try as they might, they couldn't convince her otherwise, and eventually Mycroft gave in, though Sherlock never did.