The next leaf led them home, or to what was left of it. The ruins of the Everlasting Library stood on a plain of white glass, roofless, its shelves open to the sky. Pell sneezed at the dust. Mihao did not. He stood very still, because his paws knew exactly where to go.

Behind a fallen shelf, under a rug he had not known he remembered, a stair went down into the dark.

Below the Library was another library: smaller, older, and locked from the inside. Its books were chained to the shelves, and several strained at their chains as Mihao passed. One tried to bite Pell.

These were the forbidden books, the ones even the Keeper had not dared leave on open shelves: a grammar for talking to the dead, a map of every door that leads out of a story, the true names of the stars. Some of them read you as you read them. Mihao opened one and felt it turning his pages, gently, curiously, before it shut itself with a sound very like a sigh. “That one knows you,” said Pell. “It’s sulking.”

On the far wall was a mural, faded to the colour of tea. It showed a woman in a shawl sitting in the doorway of a hut at the edge of a desert, and on her knee, a small orange kitten.

Before Wen, the mural said, the world had no stories, only things that happened and were gone. Then one night she told the kitten about her day, and at the end of it she said and then, and time, astonished, began to move forward. She told him another story, and another, and asked him to remember them all. He did. The Library grew around them, shelf by shelf, to hold what he remembered. Mihao stood before the painted kitten a long time. He did not need to be told whose ears those were.

In a glass case beneath the mural lay Wen’s own notebook, its pages soft as cloth. Most of it was lists: things to remember, things to tell the kitten, a recipe for date bread. On the last written page, in a hand that had begun to shake with age, she had left him instructions.

Keep them all, it said. The happy ones are easy to keep. But keep the sad ones too, little one. Especially the sad ones. A story with its ending cut off doesn’t go away. It just goes on hurting, somewhere you can’t see. Pell read it twice. Then she looked at Mihao, and the light in her tail went very dim.

At the back of the archive stood a desk he knew the way you know your own bed. In its drawer lay a pair of silver shears and a ledger in his own handwriting. Cut: the drowning of Ys. Cut: the last winter of the Ombre. Cut: a soldier’s letter home.

Thousands of lines. Every sad ending in the Library, snipped out so the stories would be kinder. The first entry was only a date, older than time. The last page was blank. Mihao closed the drawer and found he could not let go of it.