“I’m not . . . I can’t . . . I don’t work for Yag no more, Dee . . . I’m terminating our contract . . . I’ll explain everything, I promise, but let’s go. You’re right, we’ve stayed much too long.” He flicked his hand at the window, where the evening sounded boisterous and easygoing. “The fucking government are after us, and the biggest damn gangster on the continent . . . And the . . . the Construct Council . . .” He shook her gently.

“Let’s go. The . . . the three of us. Let’s get out and away.”

“What happened, Isaac?” she demanded. She shook him back. “Tell me now.”

He looked away quickly, and back at her.

“I had a visitor . . .” She gasped and her eyes widened, but he shook his head slowly. “Dee . . . a visitor from the fucking Cymek.” He held her eyes and swallowed. “I know what Yagharek did, Dee.” He was quiet as her face rearranged itself into a cold calm. “I know what he got . . . punished for.

“There’s nothing holding us here, Dee. I’ll tell you everything—everything, I swear—but there’s nothing holding us here. I’ll tell you while we . . . while we go.”

For days he had been in an awful lassitude, distracted by crisis maths and utterly, exhaustingly despondent about Lin. Quite suddenly, the urgency of their situation had come home to him. He realized their danger. He understood how patient Derkhan had been, and he understood that they must leave.

“Godsdamnit,” she said quietly. “I know it’s only a few months, but he . . . he’s your friend. Isn’t he? We can’t just . . . can we just leave him . . . ?” She looked at him and her face creased. “Is it . . . what is it? Is it so terrible? Is it bad enough that it . . . that it cancels everything else out? Is it so terrible?” Isaac closed his eyes.

“No . . . yes. It’s not that simple. I’ll explain when we go.

“I’m not going to help him. That’s the bottom line. I can’t, I fucking can’t, Dee, I fucking can’t. And I can’t see him, I don’t want to see him. So there’s nothing here, so we can go.

“We really must go.”

Derkhan argued, but briefly and without conviction. She was gathering her tiny bag of clothes, her little notebook, even while she said she was not sure. She was caught up in Isaac’s wake.

She scrawled a tiny addendum to the back of Isaac’s note, without opening it. Good luck, she scribbled. We will meet again. Sorry to disappear so suddenly. You know how to get out of the city. You know what to do. She paused for quite a long time, unsure of how to say goodbye, and then wrote Derkhan. She replaced the letter.