Eleanor Longstaff was dark-eyed. Long hair was being blown by the wind away from her face. She could have shared ancestors with Jimmy Perez, whose forebears were shipwrecked off Fair Isle during the Spanish Armada. The photo had been taken on the deck of the NorthLink ferry. Eleanor was dressed in a waterproof anorak and was leaning back against the rail. She was laughing. No sign here, at least, of stress or depression.

‘I can email you a copy, if that’s any good,’ Polly said.

Perez nodded and handed her his work card with his contact details. He’d get the photo printed in Unst’s small police station. Mary Lomax, the community police officer, might be away, but Sandy had brought a key to the building.

Polly’s narrow fingers were tapping on the keyboard when she stopped suddenly and looked round at them. She seemed paler than ever. Horrified. ‘I’ve had an email from Eleanor. It arrived this morning. Sent at two a.m., so not that long after we went to bed. It must be from her iPhone.’

‘Open it!’ Marcus was looking over her shoulder.

She looked at Perez for permission. He nodded and moved so that he had a better view of the screen. Polly double-clicked on the message and it opened.

No greeting and no sign-off, not even the obligatory x. Just one line. Don’t bother looking for me. You won’t find me alive.

Chapter Four

Outside there was the sound of a car moving slowly down the track. Ian’s 4x4. Polly turned off the laptop. She didn’t care what the policeman thought; she couldn’t bear the idea that Ian would walk in and find them all staring at a message from his wife. A message that could be read as a suicide note. She still couldn’t quite believe in the email; thought if she opened her in-box again it would have vanished, a figment of their collective imaginations.

Ian was a techie, a geek, not given to emotion of any kind; and even now, as he stood in the doorway frowning, it was hard to tell what he made of the situation. Polly had always thought that he and Eleanor made an unlikely couple. How could Eleanor, who needed so much love, who wanted to be touched and hugged and kissed, fall for a man so stony and unresponsive? It had occurred to Polly that her own reaction was selfish: perhaps she just hated the idea of losing her close friends of university days, of being separated from them. But Caroline had married Lowrie, who was sympathetic and uncomplicated, and Polly was entirely happy for her.

In contrast, Eleanor’s engagement to Ian had made Polly anxious from the start. The night before Eleanor’s wedding the three of them had got drunk together in Polly’s flat. The bride and the bridesmaids and too much fizzy wine. An essential ritual.

‘You do realize that it’s not too late?’ Polly had said, after Caroline had fallen asleep in a chair in the corner, her mouth open, snoring. ‘You don’t have to go through with it. Pull out now and I’ll sort out the practical stuff for you.’