Isaac was waiting for delivery of supplies. He had realized early in his reading that for the purposes of this commission there was a massive hole in his scientific knowledge. Of all the arcana, biology was his weakest. He was quite at home reading about levitation and countergeotropic thaumaturgy and his beloved unified field theory, but the prints of Teafortwo had made him realize how little he understood the biomechanics of simple flight.

What I need’s some dead wyrmen . . . no, some live one to do experiments on . . . Isaac had thought idly, staring at the heliotypes the previous night. No . . . a dead one to dissect and a live one to watch flying . . .

The flippant idea had suddenly taken a more serious shape. He had sat and pondered for a while at his desk, before taking off into the darkness of Brock Marsh.

The most notorious pub between the Tar and the Canker lurked in the shadow of a huge Palgolak church. It was a few dank streets back from Danechi’s Bridge, which joined Brock Marsh to Bonetown.

Most of the denizens of Brock Marsh, of course, were bakers or street-sweepers or prostitutes, or any of a host of other professions unlikely ever to cast a hex or look into a test-tube in their lives. Similarly, the inhabitants of Bonetown were, for the most part, no more interested in grossly or systematically flouting the law than most of New Crobuzon. Nevertheless, Brock Marsh would always be the Science Quarter: Bonetown the Thieves’ District. And there where those two influences met—esoteric, furtive, romanticized and sometimes dangerous—was The Moon’s Daughters.

With a sign depicting the two small satellites that orbited the moon as pretty, rather tawdry-looking young women, and a façade painted in deep scarlet, The Moon’s Daughters was shabby but attractive. Inside, its clientele consisted of the more adventurous of the city’s bohemians: artists, thieves, rogue scientists, junkies and militia informants jostling under the eyes of the pub’s proprietor, Red Kate.

Kate’s nickname was a reference to her ginger hair, and, Isaac had always thought, a damning indictment of the creative bankruptcy of her patrons. She was physically powerful, with a sharp eye for who to bribe and who to ban, who to punch and who to ply with free beer. For these reasons (as well, Isaac suspected, as a small proficiency with a couple of subtle thaumaturgical glamours), The Moon’s Daughters negotiated a successful, precarious trail evading any of the competing protection rackets in the area. The militia raided Kate’s establishment only rarely and perfunctorily. Her beer was good. She did not ask what was being discussed in huddles and knots at corner tables.

That night, Kate had greeted Isaac with a brief wave, which he had returned. He had gazed around the smoky room, but the person he had been seeking was absent. He had made his way to the bar.

“Kate,” he shouted over the din. “No sign of Lemuel?”