The ferry was already at Toft when they arrived and theirs was the second car in the booked lane, waved aboard almost immediately. They drank dreadful coffee from the machine in the passenger lounge, and Perez watched the fulmars flying low over the water. It felt like a day off. Truanting. He looked at his phone and asked Sandy to check his. Reception came and went here, so they might not hear even if the woman had turned up. He hoped that when they arrived at Meoness she would be there. He pictured how she would be, offering them coffee or lunch to make up for their inconvenience. Embarrassed to have caused so much fuss. A little angry with her husband for overreacting. He and Sandy would turn round and drive back to Lerwick, with only half a day wasted. But even when they arrived at Yell and the phones were working again there was still no news. Perez drove north across the island very quickly, feeling a strange sense of urgency. When they got to Gutcher a ferry was pulling out from the pier and they had to wait for the next one to arrive. He could feel the tension mounting in his forehead and across his shoulders. Fran had been thirty-six when she had died.

When they landed at Belmont in Unst a group of children was waiting to board the ferry south. He thought they must be on their way to Lerwick for some end-of-term outing. Some of them were in fancy dress. They giggled as they boarded the coach to take them to Shetland mainland. Perez was going to ask Sandy if he knew what it was about – Sandy read The Shetland Times as avidly as a gossipy woman – but the sergeant had a map open on his knee, concentrating on getting them there, and Perez thought it better not to interrupt.

The holiday house was long and low and whitewashed, and sat right on a beach with a crescent of sand and pebbles at its back. Once perhaps it had been a croft house with a byre attached, but the renovations had been well done, with the holiday market in mind. There was wooden decking between the house and the beach and a couple sat there, waiting. Perez looked at them as he got out of the car. The woman was skinny and pale. An interesting angular face, which Fran would have wanted to draw. Long hair tied back at her neck. Jeans and a cotton jumper. She walked out to greet them. ‘Is there any news? Ian has taken the car out to look for her, but that was ages ago and we haven’t heard anything since.’ Her eyes were grey and slanted like a cat’s. She had a faint north-of-England accent.

Perez introduced himself.

‘Polly Gilmour. This is my partner, Marcus Wentworth.’

‘And you were staying here with Mr and Mrs Longstaff.’

‘Yes, we came for Lowrie and Caroline’s wedding party. The four of us thought we’d make a holiday out of it, a kind of retreat.’ The eyes were almost unblinking.