“What would you do if you were on the mainland?”

“I’d talk to everyone, ask a lot of questions, understand what had happened myself, until I had sufficient evidence to take to the police.”

“You seem used to this sort of thing.”

“Yes. Before I retired I worked for the Home Office. I worked very closely with the police.”

“You must do the same thing thing here,” she said. “Ask your questions. Get to the bottom of it.”

They were both silent for a moment. The sun had nearly disappeared. The island seemed very calm and very beautiful, caught in the orange light.

“Perhaps you’re right,” he said. “I shall have to think it through for myself, be certain in my own mind first. I know that I’ve not convinced you, but if I decide to go ahead, will you help me?”

“I have to, don’t I?” she said. “I can’t give that sort of advice if I’m not prepared to follow it myself.”

“Do you know of anyone who would benefit from Mary’s death?”

“No.”

“I’ve been thinking about opportunity. Who could have left the hall without being noticed? It wouldn’t have taken very long to follow her up to Ellie’s Head, push her off, and run back.”

“To fit in with your facts the murderer must have arranged to meet her there. He or she must have given her a good reason for leaving the party.”

“Yes.”

She shook her head.

“It could have been anyone,” she said. “ Especially in the interval when the band stopped playing. People were coming and going all the time. I came out for a breath of fresh air and no one seemed to notice that I’d gone missing.”

She stopped suddenly.

“I heard footsteps while I was outside,” she said. “Running footsteps.”

“Did you? You don’t know what time that was?”

“No.”

She put her hands in her jacket pockets. “It’s getting cold,” she said. “I’d better go back to Sandwick, find Jim.”

The church bell began to ring for the evening service.

George Palmer-Jones walked with her and stopped at the gate by Sandwick.

“Don’t put yourself in an awkward position with the family,” he said. “There’d have to be a compromise anyway, whoever you married and wherever you lived. This is a special place and I don’t want to spoil it for you.”

“You won’t,” she said. Despite her Sunday-best dress she climbed the gate and ran through the mud to the house. She seemed almost excited.

Sylvia and Jonathan were still in the same positions by the fire. George felt brisk and energetic coming in from the cold, and he had an urge to rouse them from their lethargy. He had told Sarah that he would find out what had happened to the child by asking questions. He could start now.