Then she caught sight of something else that made her pause. “Your hands,” said Ruby, and Constance quickly hid them under the coat. “Let me see them. I never noticed before but …” Was she imagining it?

Constance stayed very still for a long time, looking down at her lap. Then she brought out one fist and uncurled it slowly. The skin in between her fingers was webbed.

“Have you always had that?”

Constance nodded.

“Why didn’t I see it?”

She shrugged. “People only notice the things they expect to be there.”

“Can I …” Ruby reached for the shining pelt, but Constance yanked the thing away from her.

“No, don’t touch it.”

Ruby withdrew, slightly hurt. “I wasn’t going to do anything.”

“If you touch it, something is lost. And I’ve already lost so much. Do you understand?”

Constance’s wide eyes were bright with hope, shiny with tears.

“I’m so sorry,” said Ruby. “I didn’t believe it was real. Or if it was real, I didn’t think he would have kept it. I thought you were crazy to stay here just for that.”

“He had no choice but to keep it if he wanted me alive. It would be like asking me to live without a head.”

Ruby thought she knew what Constance meant; she felt that way about her violin. More recently, she’d started to feel the same way about Leonie.

From beneath the coat, Constance brought out a white comb, carved from a shell. Ruby couldn’t understand where the comb had been hidden; the coat didn’t appear to have any pockets, or even any arms. It was more like a cloak or a long, unfilled pillowcase. Constance turned the comb over in her hand, held it out for Ruby to take.

“It’s exquisite,” said Ruby, and tried to hand it back, aware of the strange impulse she’d had to touch the coat, to possess it. Constance indicated that it was okay this time, that she should keep it.

“There’s only one like that. After I go home, that’s how you’ll find me.”

Ruby looked at the teeth of the comb, so finely crafted she was afraid they might snap if she touched them; at the shape of it, how it fitted into her palm. On the edge of it, the maker had created an intricate, intertwining mermaid pattern. It must have taken weeks of work.

“I don’t understand what you mean.”

“Don’t worry. You’ll understand when you need to.”