He got the slake-moth off Lin, he had been about to say, but something in him had preempted him, asked if that was such a good thing after all, and appalled, Isaac faltered into silence.

It’s the most powerful science for hundreds of years, he thought in a sudden rage, and I can’t come out of hiding. I have to . . . to spirit it away.

He stroked Lin’s carapace and she began to sign to him, mentioning fish and cold and sugar.

“I know, ’Zaac,” said Derkhan without anger. “I know. He’s . . . he deserves it. But we can’t wait that long. We have to go.”

I’ll do what I can, promised Isaac, I have to help him, I’ll be quick.

Derkhan accepted it. She had no choice. She would not leave him, or Lin. She did not blame him. She wanted him to honour his agreement, to give Yagharek what he wanted.

The stink and sadness of the damp little room overwhelmed her. She muttered something about scouting out the river and she left. Isaac smiled without warmth at her half-hearted excuse.

“Be careful,” he said unnecessarily as she left.

He lay cuddling Lin with his back to the foetid wall.

After a while he felt Lin relax into sleep. He slipped out from behind her and walked over to the window, looked out over the bustle below.

Isaac did not know the name of the street. It was wide, lined with young trees all pliant and hopeful. At the far end, a cart had been parked sideways, deliberately creating a cul-de-sac. A man and a vodyanoi were arguing ferociously beside it, while the two cowed donkeys drawing it hung their heads, trying not to be noticed. A group of children materialized in front of the motionless wheels, kicking a ball of tied rags. They scampered, their clothes flapping like flightless wings.

An argument broke out, four little boys prodding one of the two vodyanoi children in the group. The fat little vodyanoi backed away on all fours, crying. One of the boys threw a stone. The argument was forgotten quickly. The vodyanoi sulked a brief moment, then hopped back into the game, stealing the ball.

Further along the road, a few doors down from Isaac’s building, a young woman was chalking some symbol onto the wall. It was an unfamiliar, angular device, some witch’s talisman. Two old men sat together on a stoop, tossing dice and laughing uproariously at the results. The buildings were bird-limed and grotty, the tarred pavement punctuated with water-filled potholes. Rooks and pigeons threaded through smoke from thousands of chimneys.

Cuttings from conversations reached Isaac’s ears.

“. . . so he says a stiver for that? . . .”

“. . . damaged the engine, but then he was always a cunt . . .”

“. . . don’t say nothing about it . . .”

“. . . it’s on Dockday next, and she copped a total crystal . . .”

“. . . savage, absofuckinglutely savage . . .”

“. . . remembrance? For who?”