A few miles off. A chelona. Its titan legs were splayed, its plastron flattened to the ground. Its sides rose vastly, and from halfway up were gnarls of carapace-matter coaxed over generations into overhangs and towers, the walls of a keratin village. The great tortoise was more than a hundred yards long, and over the centuries of its life it had accreted on its back a many-layered jag township. Brittle outgrowths of its scute had been grown and carved into blocks, ziggurats and spires, their planes and lines imperfect, cut with windows, belfries connected by rope bridges, coursed with horny streets and tunnels; everything made, paved and walled in the mottlesome tortoiseshell. The chelona was dead and on fire.

It reeked of burning hair. Smoke rose from the walls in a thionic gush. Muck and gore dripped from its cave mouth.

Milling at its base were fastnesses on wheels and tracks, mobile guns-a New Crobuzon force. Crews rode two nashorns, the captains in sunk seats behind the rhinos’ heads, gripping controls sutured directly to ganglia. The militia cannon must be more powerful than they appeared to have blasted such wounds.

Militia infantry were heading in the travellers’ direction. They followed a line of refugees fleeing the remains of their chelonatown.

Drogon and Judah led them on through scrub, until a sharp coughcoughcough sounded, and there was screaming, and the echoes of bullets. They lay where they had thrown themselves until it was obvious that they were not targets, continued, staying low, to the base of a hill where they bunkered behind a marl barricade. Above them, out of the tree-cover, was a line of broken-down families. Not all were human. Some were behind fallen trunks or in hollows; some were running. Their shouts of fear were like the sounds of scraping.

At the hilltop, a corps of militia took positions. They were just discernible. They kneeled before motorguns; there was a monsoon of noise and bullets and many of the refugees fell.

Cutter watched in rage. More bullets pressed down the earth, and the dying twitched and tried to crawl away. A chelonaman raised something to his lips, and there was a thin noise, and way above there were cries and some of the militia stumbled at some thaumaturgy in the trumpet.

Drogon was watching the hilltop through his telescope. Judah turned to him in response to a whisper, and said, "She’s unpacking what?"

From the hilltop unfolded a shape of wire and dark leather, taller than a man. It became in a stutter of extending metal. Like a music stand, it unfurled many times. A humming of thaumaturgy made the air thin as a militia officer made shapes on the thing, and there was crackling, and the wire-and-hide moved.