“Not necessarily,” she said so sharply that contradiction was impossible. This was her case, and she was determined to control it in her own way. She turned again to Rob Earl.

“Tell me about Louis Rosco,” she said. “How did you come to charter his boat? Did you go in recommendation or take up references?”

“It was more informal than that,” Rob said. “He’s a friend of Rose’s. We met here. He gave me the names of some divers he’d taken out, and I checked with them. They said he was very good. He showed me round the boat. It seemed just what we wanted.”

“Do you know anything more about him?”

“No. He doesn’t talk about himself at all.”

There was a silence. She suddenly wanted to be at home with Richard. Where there was no need to pretend to be hard and competent. She pushed away the moment of self-doubt.

“You can go to bed now,” she said curtly. “I’ll talk to you again in the morning.”

Rob Earl stood up slowly and left the room. George remained seated.

“Inspector,” he said, “ there are some things you should know.”

He explained about his agency and how he had been hired by the Franks to find their son. The information was almost more than she could take in.

“What do you intend to do now?” she asked.

He paused. “ My wife thinks it would be …” He hesitated again. “… courteous, professionally correct, to visit the Franks, to explain personally as much as we know. I don’t want to interfere in your investigation.”

She looked at him with something approaching disappointment. He was grey, upright, old. She had told him that he had been a hero of hers, and that had been true. Now she only thought he was harmless. Well, she thought defensively, she was too grown up for heros now.

“I’ve no objection to your visiting the Franks,” she said. “They’ve obviously been informed of their son’s death, but I can see it might be helpful to them to talk to someone who was on the boat. Would you be able to do it in a day?”

“Yes,” he said. He thought he would not want to be away longer than that. It was the end of August, and a high-pressure system over Europe would mean migrant birds in the valleys. The intrusion of the thought shamed him, and he said nothing.

She stood up and smoothed the seams of her skirt.

“If you discover anything,” she said, “I’ll expect you to pass the information onto me.”