Ahead, there was a brief flash of yellow, a pair of eyes glowing in the moonlight. The cat observed her crashing, clumsy progress, but it didn’t seem perturbed. Breaking into a small clear space where she could see it clearly, it wandered up to the wall of the library –

– and vanished.

Alice stopped in her tracks, blinking. She could have sworn she’d seen the cat step forward, into the wall, as though it were no more substantial than fog. But that was impossible.

Fairies are impossible, she thought angrily, ripping her nightshirt free of a grasping branch and leaving a chunk of fabric behind. But I saw one, and now I’m here. What’s wrong with a cat walking through walls?

She broke free of the brush and stumbled into the clear space, leaning against the rough stone wall of the library. Her legs were a mass of pain, and something had cut the sole of her left foot so that it hurt to put much weight on it. The hem of her nightshirt was in tatters, and her hair was a tangle of leaves and broken twigs. Her breath came fast, and in spite of the chill of the night, her skin felt hot and flushed.

After a moment’s rest, she pushed herself into motion, feeling her way along the wall to where she thought the cat had been. The stone was solid under her fingers, all the way from the ground to as high as she could reach. In desperation, she slid her fingers in the cracks between blocks, looking for some kind of catch or hidden mechanism. Which is ridiculous, she thought, because how complicated could a secret door be if a cat figured it out?

There was nothing but flaking mortar in the joints. Alice gave the wall a kick with the sole of her slipper, lost her balance, and landed heavily on her bottom among the stones and weeds.

Somebody laughed, just behind her, nasty and mocking. Alice’s heart lurched, and she scrambled forward on hands and knees and pressed herself against the wall. It was suddenly very cold again.

‘It’s not going to work,’ a voice said. ‘You can’t get in that way. Because you’re not a cat, you see?’

Alice tried hard to make her tongue work, without success. It seemed to have fused to the roof of her mouth.

‘There wouldn’t be much sense in having a cat door if just anybody could use it,’ the voice said. It sounded like a young man, with a pleasantly superior accent she couldn’t quite identify. ‘A cat door should only admit cats. It seems obvious, if you ask me.’

Alice swallowed hard, pressing one hand to her chest in an effort to calm her frantic heartbeat. When she was sure she had enough breath, she whispered, ‘Who’s there?’