Yagharek strode quickly over to the window and peered out over the street five floors below. Next to the window, a little jutting column of brick extended out from the wall, becoming a chimney. A drainpipe snaked up beside it. He stood quickly on the windowsill and reached up for the guttering, tugged it quickly. It was solid.

“Isaac, bring her here,” said Derkhan urgently. Isaac lifted Lin up, biting his lip at how light she was. He walked quickly with her to the window. As he watched her, his face suddenly broke into an incredulous, an ecstatic smile. He began to weep.

From the passage outside, the slake-moth keened weakly.

“Dee, look!” he hissed. Lin’s hands were fluttering erratically in front of her as he cradled her. “She’s signing! She’s going to be all right!”

Derkhan peered over, reading her words. Isaac watched, shook his head.

“She’s not conscious, it’s just random words, but, Dee, it’s words . . . We were in time . . .”

Derkhan smiled in delight. She kissed Isaac hard on the cheek, stroked Lin’s broken headscarab gently.

“Get her out of here,” she said quietly. Isaac peered out of the window, where Yagharek had wedged himself into a corner of architecture, on a little extrusion of brick a few feet away.

“Give her to me, and follow,” said Yagharek, jerking his head up above him. At the eastern end the long sloped roof of Motley’s terrace joined with the next street, which jutted perpendicularly south in a descending row of houses. The roofscape of Bonetown stretched out above and all around them; a raised landscape; linked islands of slate over the dangerous streets, extending for miles in the darkness, sweeping away from the Ribs to Mog Hill and beyond.

Even then, devoured alive by tides of fire and acid, stunned with bolts of obscure energy, the last slake-moth might have survived.

It was a creature of astonishing endurance. It could heal itself at frightening speeds.

If it had been in the open air, it could have leapt up and spread those terribly wounded wings and disappeared from the earth. It might have forced itself up, ignoring the pain, ignoring the scorched flakes of skin and chitin that would flutter around it filthily. It could have rolled into the wet clouds to douse the flames, wash itself free of acid.

If its family had survived, if it had been confident that it could return to its siblings, that they would hunt together again, it might not have panicked. If it had not witnessed a carnage of its kind, an impossible blast of poisonous vapour that enticed its brothersisters in and burst them, the moth would not have been insane with fear and anger, and it might not have become frenzied and lashed out, trapping itself further.