The bathroom was a more recent addition, built on to the back of the house, though it had been there as long as Sandy could remember. The bath and the basin were an improbable blue, though there was still brown lino on the floor, partly covered by a bright blue shaggy rug. A smell of damp and wet towels. An enormous spider crawled around the plughole. Otherwise the room was empty.

Sandy tried to think rationally. He’d dealt with missing-person inquiries and knew that families always panicked unnecessarily. He’d made fun of the anxious parent or partner once he’d put down the phone. ‘There was a party at the Haa last night. That’s where they’ll be.’ But now he felt the shock of the unexpected, the unknown. Mima never strayed from her house at night these days, unless there was a family do at his parents’ house or a big island event like a wedding, and then someone would have given her a lift and he’d know about it. She had no real friends. Most Whalsay folk were slightly afraid of her. He felt his thoughts spinning out of control, tried to keep calm. What would Jimmy Perez do in this situation?

Mima always shut her hens up at night. Maybe she’d gone out to do that and tripped and fallen. The archaeologists had dug their trenches on some land right away from the house, but she was getting on now and it was possible that the drink was at last clouding her judgement. If she’d wandered down that way it would be easy enough to lose her footing.

Sandy went back to the kitchen and collected a torch from the drawer in the table. It had been there from the time when every house had its own generator, which only ran for a couple of hours in the evening. Outside, he felt the chill of the mist and drizzle, biting after the heat of the Rayburn. It must be nearly midnight. His mother would be wondering where he was. He walked round the house. Here was the shed where Mima brought in the cow for milking. Once his eyes adjusted to the dark there was enough light spilling from the house for him to see quite clearly where he was going. He’d left on the bathroom light and the window faced this way. No need yet for the torch. The hens were already shut up. He checked the catch on the wooden henhouse and could hear the rustle of movement inside.