“If the city comes to a stop, the variables will ebb almost to nothing. The flow of information will dry. I do not wish to live in an empty city. I have fed the variables of the slake-moth problem into my analytical network. The outcome is straightforward. Unchecked, the prognosis for bloodlife in New Crobuzon is extremely bad. I will help you.”

Isaac looked to Derkhan and Lemuel, took in Yagharek’s shadow-hidden eyes. He looked back at the shivering avatar. Derkhan caught his eye. Tread carefully, she mouthed exaggeratedly at him.

“Well, we’re all . . . damned grateful, Council . . . uh . . . how . . . Can I ask what you intend to do?”

“I have calculated that you will best believe and understand if I show you,” said the man.

A pair of massive metal clamps snapped into position on Isaac’s forearms. He yelled out in surprise and fear and tried to turn. He was held by the largest of the industrial constructs, a model with hands designed to connect to scaffolding, to hold up buildings. Isaac was a strong man, but he was quite incapable of breaking free.

He cried out to his companions to help him, but another of the huge constructs stepped ponderously between him and them. For an unclear moment, Derkhan and Lemuel and Yagharek hovered confusedly. Then Lemuel broke and ran. He raced away down one of the long trenches in the rubbish, peeling away to the east, out of sight.

“Pigeon, you bastard,” screamed Isaac. As Isaac struggled, he saw with amazement that Yagharek moved before Derkhan. The crippled garuda was so quiet, so passive, such a cypher of a presence, that Isaac had discounted him. He would follow, and he might do as he was asked. That was all.

And yet here was Yagharek now leaping up in a spectacular sideways motion, sliding round the side of the guarding construct, scrambling for Isaac. Derkhan saw what he was doing and moved the other way, causing the construct to dither between them, then stride purposefully towards her.

She turned to run, but a steel-sheathed cable whipped up like a predatory snake from the trash-undergrowth and whiplashed around her ankle, pulling her to the ground. She fell hard across the shattered ground, cried out in pain.

Yagharek was scrabbling heroically with the construct’s clamps, but it was quite ineffectual. The construct simply ignored him. One of its fellows moved in behind Yagharek.

“Yag, dammit!” shouted Isaac. “Run!” But he spoke too late. The newcomer was a similarly enormous industrial construct, and the wire-mesh that looped down and ensnared Yagharek was much too hard to break.

Out of the fray, the bloody man, that flesh-extension of the Construct Council, raised his voice.

“You are not being attacked,” he said. “You will not be harmed. We start here. We lay bait. Please do not be alarmed.”

“Are you out of your godsdamned mind?” shouted Isaac. “What the fuck d’you mean? What are you doing?”