‘Of course I don’t want to pull out.’ Eleanor had been horrified, had looked at Polly as if she hardly knew her. ‘Ian’s what I want and what I need. I can’t imagine not spending the rest of my life with him. What’s wrong with you? Can’t you be happy for me? Are you jealous that I’ve found someone special at last?’

That had been three years ago and it still seemed to Polly that their friendship was strained. Caroline hadn’t noticed, but Polly had been aware of the tension, of having to choose her words carefully. She couldn’t spill out her feelings to Eleanor as she had in the old days, when they’d both been single. She’d hoped this trip to Unst might make everything between them right again.

Of course Eleanor’s wedding to Ian had taken place and Polly had been there as the witness, smiling for the camera outside the registry office on a breezy March day. Eleanor had changed her name to her husband’s, although few of their friends did that any more. In the afternoon they’d gone up in the London Eye and had drunk a toast in champagne to Mr and Mrs Longstaff. Then Eleanor had sent the guests away to party without them. ‘My husband and I want to be alone.’ A radiant smile.

Caroline’s marriage had brought back all the memories of that time, and Polly remembered Eleanor’s wedding again as Ian stood, solid and angular, in the doorway of the house. She had a brief and ridiculous idea. Two weddings and a funeral. She realized that the start of a grin was appearing on her face and knew it was caused by stress, but was horrified all the same.

The police officer with the Spanish name spoke first. He stood up and introduced himself to the newcomer. ‘You didn’t see anything of your wife on the island?’

Ian shook his head. He was always a man of few words. Now he seemed frozen. ‘I went up to Lowrie’s house, but there was nobody there. I tried phoning, but it went straight to voicemail.’

‘Our volunteer coastguards are out looking,’ Perez said.

Ian nodded, but didn’t move from his place by the door.

‘Let’s walk,’ Perez said. ‘I always find it easier to think when I’m walking.’

Polly thought that he was a sensitive man. He wouldn’t want to tell Ian about the email from Eleanor in front of an audience.

Ian turned and the two men left the house. Polly and Marcus stayed in the living room with Perez’s younger colleague. Marcus got up to make more coffee. He collected the tray from outside and walked with it to the kitchen. Polly wanted to apologize to him. I should never have brought you here. I thought it would be fun and a good way to get to know my friends. Now it’s turned into the worst sort of nightmare. But Wilson, the young sergeant, was watching and listening, and in these circumstances anything she said might be misinterpreted.