The next leaf led them to a city that was not there. From the road it looked like a hillside and some low cloud. Only when Pell walked straight into a gatepost did they find the walls: tall, white, perfectly real, and hung with banners that had nothing on them at all.

Inside, people went about their business: hares, mostly, in good coats, buying bread and arguing about the weather. Not one of them knew what their kingdom was called.

The kingdom was run, very efficiently, by its Chancellor. Mordal Vane was a long grey stoat in a long grey coat, and he received them in a throne room where the throne itself stood empty under a dust sheet.

“There is no king,” he said smoothly. “There has never been a king. Orrin governs itself, with a little help.” He smiled with a great many teeth. But Pell had gone very still, staring at the throne. “Somebody’s been cut out of here,” she breathed. “I can see the edges.” Mihao looked at the Chancellor’s paws, folded over a ledger, and at the faint papery whiteness on his claws, as if he had been handling something not entirely there.

That night they crept into the Long Gallery. Portraits of the old kings and queens of Orrin hung along it, robed and crowned and painted with great care. Every single face had been removed.

Not scratched off. Not faded. Removed, cleanly, as if lifted out with a blade. Pell ran her nose along the edge of the nearest canvas. “It isn’t eaten,” she said. “The Hollow eats things. This was cut.” She looked up at Mihao, and her ears went flat. “With scissors. Very good scissors. The kind only a…” She stopped. Mihao did not ask her to finish. Somewhere deep in his memory, something silver closed with a small, neat snick.

Behind the gallery they found the princess. Her name was Iselde, she was eleven, and she was disappearing. Her paws were already as faint as breath on glass. The Chancellor had been feeding her name to the Hollow in exchange for its help, one syllable a year, and nobody in Orrin remembered there had ever been a princess to miss.

She was not frightened. She was furious, which Mihao liked very much. “He says a kingdom only needs rules,” she said. “But rules are just a story nobody’s allowed to argue with.” She held out a fading paw. “Can you write me back in, old cat? Before I’m gone?”

The Charter of Orrin lay in the Chancellor’s desk, every ruler’s name snipped out of it. With a beard-hair for a pen, Mihao wrote them back from the memory of the old trees, kings and queens and one princess, and the banners outside filled with colour.

Mordal Vane fled into the Hollow, and the Hollow spat him out a moment later, blank as a new page. Then, for the first time, it spoke, through the Chancellor’s empty mouth. Keeper, it said. You left the door open.