On the deck Sandy had been joined by Polly.

Now Ian was close enough to shout. ‘Where is she? Have you found her?’ Perez sensed the desperation in his voice.

Sandy didn’t reply.

The women had left Eleanor’s phone in the planticrub, with Caroline to keep guard of it. At least the spate of US crime shows had made people aware that a possible crime scene shouldn’t be disturbed. Walking along the sheep track on the top of the cliff, Perez tried to work out what the discovery of the phone might mean. Ian had told him that he’d tried to call Eleanor as soon as he’d realized she was missing: ‘Of course I tried to get in touch with her. It was the first thing I thought of. And I’ve been trying ever since. But there was no answer.’

Why did the woman no longer have her phone? And did this mean that someone other than Eleanor had composed the email to Polly Gilmour? Perez repeated the words in his head. Don’t bother looking for me. You won’t find me alive. He ran through explanations for the message, which grew wilder and more improbable: a killer setting up the scenario that Eleanor had committed suicide; someone playing a tasteless and elaborate joke. One thing was certain. Eleanor was still in Unst, whether she was alive or dead. The ferry boys had already told Sandy that nobody matching her description had left the island that morning.

Lowrie’s new bride was sitting on the grass outside the crub, but scrambled to her feet when she saw him approach. She looked to Perez very English, strong and healthy, with curly fair hair and good white teeth. He could imagine her running up a hockey field and cheering her team on. And when she spoke there was a no-nonsense tone to the voice.

‘Is Polly OK? I didn’t want to send her off on her own, but I thought someone should stay here. Scare off the sheep. And any stray walkers.’ If she was upset about Eleanor’s disappearance there was no sign of it. But perhaps not showing emotion was part of her character too.

‘Polly’s with Marcus.’ Perez paused. Marcus had been comforting the woman as if she were a child, offering to wrap her in a rug, to make her herbal tea. ‘She’s distressed of course, but she seems fine.’ He looked over the wall. ‘You’re sure that belonged to Eleanor?’

‘I haven’t touched it to look at the call records,’ she said, ‘but it’s certainly the same model and colour.’

He put on gloves and reached over the wall to retrieve the phone. It came to him suddenly that he was treating this as a potential murder scene and that he had no expectation of Eleanor being found alive. If the phone had lain here for most of the night in a heavy dew there’d be little chance of fingerprints, though, and any of her friends could have touched it over the previous few days. The battery was low, but there was sufficient signal to see the email to Polly in the Sent box and the record of missed calls from Ian. There’d been no other calls or emails sent or received since.