Ladia and the residents scattered. Ori ran for Jacobs, but to his surprise the old man walked past him with purpose but no urgency. He did not look at Ori or anywhere but ahead. He walked quickly past the last milling homeless, while at the street’s end was the sound of battle and in the dark only a rapid and ugly mass of black figures. Jacobs turned the other way, toward Saltpetre Station and the raised arches that climbed north over the city.

Ori hesitated, thinking that there was perhaps nothing left to speak to in that shell, and then realising that he wanted to see where the man would go and what he would do. In the very dark of New Crobuzon without its lamps, Ori followed Spiral Jacobs.

He did not stalk him like a hunter but merely walked a few steps behind. He tried to place his shoes down soft enough that his step was only a ghost-echo of the mendicant’s shuffling. They were the only people in the street. They walked between a fence of wood and iron on one side, damp bricks on the other, rising scores of feet above their heads. Spiral Jacobs skipped, treaded forward singing a song in an alien key, wandered back some steps, ran his fingers, poking from the cutoff ends of his gloves, over the corrugated iron and rubbed at its rust, and Ori came behind him as respectful and observant as a disciple.

With a thumb of chalk, Spiral Jacobs drew the shape that had given him his name, whispering while he did, and it was of astonishing perfection, a mathematical symbol. And then there were curlicues, smaller coils coming from its outer skin, and Jacobs ran his hand over it, and walked on.

It began to rain as Ori reached the mark Jacobs had made. It did not smear.

Past the tumbledown brick arch of Saltpetre Station and on toward Flyside into a place where the gaslamps had not given out, where guttering dirt-light returned to tan the walls and doors into grotesques. The old man wrote his shapes. He wrote on window, once, the grease of whatever he was using gripping the shine. A rut of street closed up to Ori and funnelled him through a brick arch after his idiot guru, into a wider zone of pallid light where the gas was effaced by the elyctro-barometrics, cold lurid colours, red and gold made ice in knotted glass.

They were not alone now. They were in some dream-dark landscape. Ori wondered when his city was taken, made this.