‘Let’s check if it’s locked before we trouble him.’ She felt he was indulging her as he might have done Cassie. There was a small arched door at the foot of the tower. The handle was stiff but eventually it turned. Inside, a stone staircase spiralled around the outer wall. There was no light, except from the door that Perez had propped open – and that grew fainter as they climbed – and then from a small window further up. Fran felt the muscles in the backs of her legs strain and stopped for a moment to catch her breath. Ahead of her Perez seemed not to feel the exertion. He continued and must have reached the top and opened a door into the lens room because suddenly the shaft of the tower was flooded with light. She followed him.

She’d been right. The view was astounding and the island was spread out beneath them like a three-dimensional map. The jagged forks of cliff made sense, the road twisted past the northernmost crofts, which she could now recognize by name. Even if we never come to live here, she thought, this is always going to be a special place for me. I kind of belong. She saw the Land Rover being used by the search team making its way back to the field centre. Then, turning to the west, she saw Sheep Rock again, from a different and arresting perspective. She took a sketchpad from her bag and began to draw, very quickly, her forehead pressed against the glass.

‘You don’t mind the height then?’ Perez said. ‘After the plane I thought you might have a problem with vertigo.’

She turned briefly to smile. ‘In the plane I thought I was going to die. A reasonable fear in the circumstances.’

Perez looked briefly over the island but soon turned his attention to the north and west. ‘You can see the lighthouse at Sumburgh Head and the Foula cliffs.’ Fran was so focused on her sketch that she hardly heard him.

When she saw him again, conscious of a silence, a lack of movement, he was peering under the wooden bench that ran round the room, under the windows. He must have sensed her looking at him. ‘What do you think that is?’

‘Don’t know. A bit of rag.’ Her head was still full of the painting she was planning. She thought it might be her best work ever. Would it be possible to exhibit it before she gave it to James and Mary?

‘White cotton certainly. A pillowcase, do you think?’

‘You’re thinking it might have held the feathers scattered over Jane’s body?’