She’d expected an expression of grief, horror. Even strangers seemed to think a response was needed when they heard of a violent death. But Craggs’s reaction seemed dramatic. The colour appeared to drain from his face and he sat suddenly on the stool by his side.

‘Poor Margaret. What a terrible way to die.’

‘You knew her well?’

He took a while to answer. ‘I’ve been researching in the waters off Mardle since I was an undergraduate, and I’ve stayed at the guest house in Harbour Street at least one night a month since it opened. Kate and Margaret felt almost like a second family. Kate must be devastated. Even now that she has a new partner, I’m not sure how she’ll cope there without Margaret.’ A pause. ‘Do you know who killed her? I’m not sure how you think I could help.’ He sat with his elbows on the bench. Holly saw that his blue rib-knit sweater had been neatly darned. There was a splash of something that might have been egg on the front of it. He looked like an absent-minded professor from children’s stories.

‘We’re talking to all the regulars at the guest house.’

‘Of course.’

‘When did you last see her?’ Holly took a seat herself. They faced each other across the bench. There was a background smell of chemicals and something organic.

‘At breakfast yesterday. She cleared my table as usual.’

‘How did she seem?’

‘Just as she always seemed.’ Craggs played with his wedding ring, turning it on his finger. ‘Polite, helpful, cheerful. I had an early breakfast because I had a full day ahead of me. If there were other guests, they hadn’t appeared by the time I left.’

‘You didn’t have any impression then that she was upset or anxious.’

‘No, but then I probably wouldn’t have noticed. We don’t often notice the people who look after us, do we? Though we’d miss them if they weren’t there.’

Holly thought he was a strange man. She wondered if he was quite as sharp as a modern professor should be. She couldn’t imagine him fighting his corner with university politics or pulling in overseas students prepared to pay high fees. ‘We’re having problems tracing her family,’ she said. ‘Did she mention anyone to you?’

Again he took a while to consider before he answered.