Isaac leaned against his desk. He ran his fingers over the diagrams that littered its surface. At the top was a scribbled triangle containing a cross. He closed his eyes against the continuing cacophony.

“Oh shut up, all of you,” he yelled, but the animal chorus went on as before. Isaac held his head in his hands, his frown growing more and more piercing.

He was still stinging from his disastrous journey to Spatters the day before. He could not help running over the events again and again in his mind, thinking about what he could and should have done differently. He had been arrogant and stupid, wading in like an intrepid adventurer, flailing his money as if it were a thaumaturgic weapon. Lin was right. It was no wonder he had managed to alienate probably the city’s entire garuda population. He had approached them as a gang of rogues to be wowed and bought off. He had treated them like cronies of Lemuel Pigeon. They were not. They were a poor, scared community scrabbling for survival and maybe a scrap of pride in a hostile city. They watched their neighbours picked off by vigilantes as if for sport. They inhabited an alternative economy of hunting and barter, foraging in Rudewood and petty pilfering.

Their politics were brutal, but totally understandable.

And now he had blown it with the city’s garuda. Isaac looked up at all the pictures and heliotypes and diagrams he had made. Just like yesterday, he thought. The direct approach isn’t working. I was on the right track at the very start. It’s not about aerodynamics, that’s not how to proceed . . . The squalls of his captives intruded on his thoughts.

“Right!” he shouted suddenly. He stood up straight, and glared at the trapped animals, as if daring them to continue with their noise. Which, of course, they did.

“Right!” he shouted again, and strode over to the first cage. The brace of doves inside puffed and billowed explosively from one side to the other as he tugged them over to a large window. He left the box facing the glass and fetched another, within which a vivid dragonfly-snake undulated like a sidewinder. He placed that one on top of the first. He grabbed a gauze cage of mosquitoes, and another of bees, and dragged them over too. Isaac woke cantankerous bats and aspises basking in the sun, pulled them over to the window overlooking the Canker.

He cleared all his remaining menagerie over to that pile. The animals looked out at the Ribs, which curved cruelly over the eastern city. Isaac piled all the boxes containing living things into a pyramid in front of the glass. It looked like a sacrificial pyre.

Eventually the job was done. Predators and prey fluttered and screeched next to each other, separated only by wood or thin bars.