There was no sign of Lowrie’s parents.

‘I know’, she said, ‘that it’s ridiculous, and I’m sure there’s a rational explanation. But Eleanor’s been so fragile lately. Losing the baby and all that talk of haunting and ghosts. When the policeman said you’d all be in the hall, I thought, Of course, she’ll be there. I couldn’t stand being in that house any longer. And then, when you hadn’t seen her, I knew something dreadful must have happened.’

The room was very warm and she felt that she might fall asleep in the hard chair, and when she woke up all this would be a dream.

‘I’ll walk back with you,’ Caroline said. ‘There might be some news.’

Her voice sounded hard, detached, as if she didn’t care about Eleanor at all. Why wasn’t she more upset? Polly had the idea that Caroline just wanted her out of the house before her in-laws returned. Perhaps a hysterical friend would reflect badly on her. Caroline was an academic, always measured and precise. It also occurred to Polly that Caroline might not believe her story and that she wanted to check out the facts of Eleanor’s disappearance for herself.

They took a different route back to the holiday cottage. Caroline led the way through the garden where hens scratched behind wire mesh, over a stile and onto short cropped grass. She seemed very at home here.

‘Would you ever live in Shetland?’ Polly asked suddenly. ‘Would Lowrie want that?’

‘Maybe. If I could think of something to do all day. We’ve talked about it. I wouldn’t want to bring up kids in the city.’ Caroline gave a sudden grin. ‘He has this idea about setting up a business here. Soft fruit grown in polytunnels. High-end jams and preserves.’

‘And you wouldn’t mind that? Leaving behind your friends. And everything that goes with being in town. Theatre on your doorstep. Shops and bars and restaurants. Even Lerwick’s miles away.’ Polly found herself distracted from her anxiety by this new Caroline, who wore wellingtons, could negotiate a barbed-wire fence with ease and could contemplate making a home in this barren landscape where the seasons were so extreme.

‘Ah, we might have to compromise on the exact location. Unst might be a step too far for me. And I love Grusche and George to pieces, but I wouldn’t want to be next door to the in-laws.’ She paused for a moment and looked back over the croft. ‘Sometimes Grusche treats Lowrie as if he is nine years old and can’t clean his teeth without being reminded.’

They came to the brow of a low hill and Polly got her bearings. She could see the track to their house and the beach ahead of them. Ian and Perez were still on the sand, but they were heading back to Sletts. There was a view south of cliffs and headlands.

‘If Eleanor fell over a cliff,’ she said suddenly, ‘she could lie on the rocks below for days without being found.’