“Oh, they did, they did!” cries Mrs Fossil, clutching her knees. “They said it would only be for an hour or so. They said they wanted to walk down to the wreck of the battleship while the tide was out. It seemed romantic, so I didn’t ask why. Your dad and I were old pals from way back, and I was out beachcombing for amber with my UV torch and didn’t mind having a little baby bundled in a sling inside my coat. It was cosy!”

“But what happened?” says Vi, standing up. “What happened exactly?”

“That’s just it,” says Mrs F. “I don’t know. I agreed to be on the harbour wall when they got back. But, well, there was some good amber washed up that night, really A-grade stuff, and I suppose I walked a bit too far, or lost track of time or something. When I went back to meet them, they weren’t there. Just their shoes.” And she dissolves into tears. “I never saw them again!”

Violet goes and stands over Mrs Fossil. Then she puts her arm around her.

“It’s not your fault,” she says. “Maybe they lost track of time too. Or misunderstood something. That’s not hard to do when the tide is out and the mist rolls in.”

Mrs Fossil screws a well-used piece of tissue onto her nose and blows a honk.

“Afterwards, when they didn’t reappear, I went back to the hotel, but they weren’t there either. That’s when I started to panic. I sneaked into your parents’ room and left you in your cot. You were sound asleep. Then I made an anonymous call to the police.”

“Anonymous?” I say. “But why?”

“I don’t know what I was thinking,” says Mrs F. “I was just terrified it was my fault somehow. That wreck is so dangerous. And maybe it would look like I was kidnapping you. I thought the coastguard would find them, and that it would all be sorted out in a jiffy. Then, when it wasn’t, when the police arrived, I was too scared to come forward. I’m so, so sorry.”

“It’s OK, Mrs Fossil,” says Violet, hugging her again. “Or may I call you Wendy?”

ERWIN’S PAW

I DON’T KNOW WHAT it is that makes me look out of the shop window just then. But look out I do, and I see in the thin light of dawn two figures – one sitting, one standing – near the statue in the middle of Dolphin Square.

I leave the others chatting, and walk to the door, grabbing my Lost-and-Founder’s cap as I go. I’m unable to quite believe my eyes.