The drive was by turns awe-inspiring and bleak: coastal vistas giving way to interior moorland, scattered settlements, a lot of sheep – many of them on the road – and few trees. Jack was right though, the sky was amazing. Forres had told them this season was ‘simmer dim’ – a time of year without true darkness. But in winter, daylight became a precious commodity. You had to respect people who chose to live miles from everything you took for granted. Easy enough to be a hunter-gatherer in a city, but out here … It wasn’t the sort of scenery to inspire conversation. They found their dialogues crumbling into grunts and nods. As close as they were in the speeding car, they were in isolation each from the other. No, Rebus was damned sure he couldn’t survive out here.

They took a left fork towards Brae, and found themselves suddenly on the island’s west coast. It was still hard to know what to make of the place – Forres was the only born and bred Shetlander they’d met. What architecture they’d seen in Lerwick had been a mix of Scottish and Scandinavian styles, a sort of Ikea baronial. Out in the country, the crofts were the same as any in the Western Isles, but the names of the settlements showed Scandinavian influence. As they drove through Burravoe and into Brae, Rebus realised he felt just about as foreign as he ever had in his life.

‘Where to now?’ Jack asked.

‘Give me a minute. When I was here before, we came into town the other way …’ Rebus got a fix on where they were, and eventually led them to the house Jake Harley shared with Briony. Neighbours looked out at the police car like they’d never seen one before; maybe they hadn’t. Rebus tried Briony’s door – no answer. He knocked harder, the sound echoing emptily. A look in through the living-room window: untidy, but not a mess. A woman’s untidiness, not quite professional enough. Rebus went back to the car.

‘She works at the swimming pool, let’s give it a shot.’

The pool, with its blue metal roof, was hard to miss. Briony was pacing the edge of the pool, watching children at play. She wore the same uniform of singlet and jogging bottoms as when they’d last met, but now had tennis shoes on her feet. Her ankles were bare: lifesavers didn’t bother with socks. She had a referee’s tin whistle strung around her neck, but the kids were behaving themselves. Briony saw Rebus and recognised him. She put the whistle in her mouth and gave three short blasts: a recognised signal – another staff member took her place poolside. She walked up to Rebus and Jack. The temperature was getting on for tropical, with humidity to match.

‘I told you,’ she said, ‘Jake’s still not shown up.’

‘I know, and you said you weren’t worried about him.’

She shrugged. She had short dark hair which fell straight most of the way before ending in kiss-curls. The style took half a dozen years off her, turning her into a teenager, but her face was older – slightly hardened, whether by climate or circumstance Rebus couldn’t say. Her eyes were small, as were nose and mouth. He tried not to think of a hamster, but then she twitched her nose and the picture was complete.