He tried to think himself away from the whole thing. He told himself desperately that to refuse his services would not imply judgement, that it would not mean he pretended knowledge of the facts, that it would simply be a way of saying, “This is beyond me, this is not my business.” But he could not convince himself.

He slumped and breathed a miserable moan of exhaustion. If he turned from Yagharek, he realized, no matter what he said, Isaac would feel himself to have judged, and to have found Yagharek wanting. And Isaac realized that he could not in conscience imply that, when he did not know the case.

But on the heels of that thought came another; a flipside, a counterpoint.

If withholding help implied negative judgement he could not make, thought Isaac, then helping, bestowing flight, would imply that Yagharek’s actions were acceptable.

And that, thought Isaac in cold distaste and fury, he would not do.

He folded his notes slowly, his half-finished equations, his scribbled formulae, and began to pack them away.

When Derkhan returned, the sun was low and the sky was blemished with blood-coloured clouds. She tapped the door in the quick rhythm they had agreed, bundling past Isaac when he opened it.

“It’s an amazing day,” she said with sadness. “I’ve been sniffing quietly all over the place, getting a few leads, a few ideas . . .” She turned to face him and was instantly quiet.

His dark, scarred face bore an extraordinary expression. Some complex composite of hope and excitement and terrible misery. He seemed to brim with energy. He shifted as if he crawled with ants. He wore his long beggar’s cloak. A sack sat beside the door, bulging with heavy, bulky contents. The crisis engine was gone, she realized, disassembled and hidden away in the sack.

Without the spread-out mess of metal and wire, the room seemed utterly bare.

With a little gasp, Derkhan saw that Isaac had wrapped up Lin in a foul, tattered blanket. Lin clutched at it fitfully and nervously, signing nonsense up at him. She saw Derkhan and jerked happily.

“Let’s go,” said Isaac in a hollow voice that strained with tension.

“What are you talking about?” said Derkhan angrily. “What are you talking about? Where’s Yagharek? What’s come over you?”

“Dee, please . . .” whispered Isaac. He took her hands. She reeled at his imploring fervour. “Yag’s still not come back. I’m leaving this for him,” he said, and plucked a letter from his pocket. He tossed it nervously into the centre of the floor. Derkhan began to speak again and Isaac cut her off, shaking his head violently.