“Last weekend,” she said. “ It was all rather sudden. I was pleased; I thought he could do with a holiday. There’s a lot of pressure on the sites of scientific interest in the area, and he’s been under strain for months.”

“How did he come to hear of the trip?”

“I don’t know exactly,” she said. “I presume it was some sort of circular. A letter came for him on Saturday morning, and later that day at dinner he said something like ‘This looks interesting. Would you mind if I went?’”

“Did you read the circular?”

“No,” she said. “But if you want to see it, I expect it’s still in Duncan’s office. He never throws anything away.”

She stood up and, with a last look at the children, led him into the house. He thought it was her confidence which made her so trusting. She was so secure that she believed this relative stranger could do her family no harm. Inside it was cool, ordered, cared for, without being uncomfortably tidy. Children’s Wellingtons stood in a row just inside the door. Anne must have been picking apples, because there was a box of them, wrapped separately in newspaper, in the hall. Duncan’s study was a mess of papers and files. An open ordnance survey map was spread over the floor, and they had to step over it to get to the desk. On the desk a rack of plastic trays was spilling over with letters. “It’ll be here somewhere,” she said, working through the papers in the top tray. “It’s doesn’t look like it, but there’s a kind of system.” He watched her pile letters and bills into some kind of order. “ Here we are,” she said. “This is the telephone bill. It came on Saturday, too.”

“What’s that?” George said, pointing to a printed white envelope.

She opened it and pulled out a glossy brochure.

“No,” she said. “ This is an advertisement for a new leisure complex in the county. There’s been controversy over it for years, since the original plans were proposed. It’s in the middle of Rashwood Park. Duncan supervised the environmental impact assessment. There was a lot of opposition to the project locally, but unfortunately he couldn’t find any habitat rare or important enough to stop it going ahead.”

“Could I have a look?” George asked.

The development company was called Squirrel, and the publicity was emblazoned with a logo of oak leaves and acorns. The complex included a four-star hotel and golf course, a health club and gymnasium. It had been open for six months, and the photographs showed scrawny middle-aged women drinking cocktails by a swimming pool. On the border of the front page, in red ink, was written a Bristol phone number.

“Did this arrive on Saturday?” George asked.

“Yes,” Anne said vaguely. “It must have. It was next to the telephone bill.”

“Did you see Duncan open the circular about the Jessie Ellen trip?”