‘Did she see you?’ Perez tried to picture the scene in the restaurant and thought that Caroline was making too much of it. Eleanor could have been reassuring a young colleague about a problem at work. A touch of the hand could be a gesture of friendship. It didn’t have to be intimate.

‘No,’ Caroline said. ‘It was a few months ago. She had her second miscarriage just before Christmas, and this was March or April. Late enough for it to be dark outside. One of those drizzly days that feel more like midwinter. She hadn’t long sprung herself from the hospital. She wouldn’t have seen me.’

‘Did you discuss it with her?’

‘Yes.’ Caroline paused. ‘She lied. You must have been mistaken, Caro. I was in Brussels that week. I wasn’t even in London. Her voice all brittle and tense. I let it go. But I wasn’t mistaken. It was definitely her.’ She looked up at Perez. ‘That was when I knew this new man must be important, you see. If the dinner was just a work meeting, or even if she was having a fling or a one-night stand, she’d tell me and swear me to secrecy. But she lied and she’d never done that to me before.’ There was another pause. ‘Since then Eleanor seems to have been trying to avoid me. I think she’s met up on her own with Polly a couple of times, but I’ve only seen her when other people have been around.’

‘If Eleanor were planning to leave her husband,’ Perez said, ‘I don’t quite understand why she would wait until she was in Shetland to do it. It’s so much more inconvenient here.’

Caroline gave a tight smile. ‘Eleanor’s never planned to do anything in her life. It would have come to her in the middle of a dance; or maybe when she saw Lowrie and me together she realized that her life with Ian was impossible. That she couldn’t stand it any longer. Then she would have walked away. Without thinking through the consequences. Have you tried the guest houses in Unst? If she hasn’t left on the ferry, she might be fast asleep on a comfortable bed. Eleanor has always liked her comfort.’

‘Without taking her toothbrush or her moisturizer?’

For the first time Caroline looked a little shaken. ‘Ah,’ she said. ‘That doesn’t sound so much like the Nell I know.’ She reached for the pot in the middle of the table and poured out more tea.

Outside there was a noise. The bark of a dog and running footsteps. A man crashed through the door into the kitchen. He was wheezing from running and his face was red. He bent double and tried to catch his breath to speak. Caroline stood up and stroked the hair from his forehead. She could have been comforting an anxious child.

‘We’ve found her! I need to tell the police.’ Then he noticed Perez, sitting in the shadow. ‘Who are you?’