The twins were in bed when it happened. They heard a sound like a wet cabbage hitting a wall, then a clattering on roof tiles – then nothing but the wind wuthering around the eaves once more.

“What was that?” whispered James.

Amanda, who slept behind a curtain on the other side of the attic, switched on her bedside light, and they lay very still, listening.

Rap, rap! Came a knock on the skylight.

“Who’s there?” said James. He climbed out of bed and stood under the window, and there he saw a startled face framed by a tangle of windblown hair. “It’s a girl!” he cried.

Together, the twins dragged the big red chairs across from the corner, and James stood on it to reach the latch.

“Open up!” yelled the girl in a muffled voice.

James opened the window and a gust of rain blew into the room. “Thanks,” gasped the girl, climbing in – and a moment later, she was standing there before them, dripping on the carpet. To the twins’ astonishment they saw that she was barefoot and wearing only a thin white cotton dress. But most astonishing of all, hanging from her shoulders and reaching nearly to her feet was a pair of long white wings.

“Ow!” moaned the girl, clutching her left shoulder. “I think I’ve broken my wing.”

James and Amanda helped the girl with the broken wing to the sofa, where she sat down carefully. “I’ll have to lie on my front,” she said.

So Amanda brought a pillow and the girl lay down, with her long white wings folded neatly along her back. The tips of the wings lay on her calves, and the downy feathers at her shoulders were sticky with rain. Amanda reached out her hand and stroked one of the wings gently. It felt firm and springy, like stroking a swan.

“What’s your name?” asked Amanda. The girl with the broken wing yawned. “Hilary,” she said.

“I’m Amanda,” said Amanda politely. “And this is my brother, James.”

“Nice to meet you, murmured Hilary, snuggling deeper into the pillow.

“Um – Hilary,” said James, “what were you doing on our roof?”

Hilary mumbled something that neither of them could quite make out, then closed her eyes.

“Excuse me?” said James. But there was no reply. Hilary’s breathing had settled into the regular, easy rhythm of sleep.

“She’s in shock,” said Amanda. “We can ask her again in the morning.”

Then, just as they were about to turn away, Hilary opened her eyes and spoke again – quite clearly this time.