“I was interested in the birdwatching element,” he said. “ I work as regional officer for the Nature Conservancy Council, but ornithology isn’t really my subject. I thought this holiday would be an excellent introduction. My patch covers the whole of the south-west peninsula, and it did seem important to learn a little about seabird identification.” He was rather proud of his answer, and it gave him confidence. Only the sergeant, sitting out of sight, half-hidden by a giant rubber plant, gave Duncan some cause for concern. He had calm blue eyes, and Duncan had a guilty sense that the sergeant could tell when he was lying.

“When did you decide to come to Heanor?” the inspector asked.

“Only last week,” he said. “It was an impulse. I had a few days’ leave to take. I was lucky there was still a place available.”

“Yes,” she said. “ I see. How did you hear about the trip?”

“I’d read about them in the natural history press,” he said. “They’re quite famous, you know.”

“Had you met Greg Franks before?”

“Not as far as I’m aware,” Duncan said. “I may have met him through my work. I come across pressure groups and representatives of natural history societies occasionally, but having met Greg, I doubt if he was involved in that kind of thing. And besides, I think I should have remembered him if I’d seen him before. He was quite an exhibitionist.”

There was a pause.

“What effect did that exhibitionism have on the other passengers?”

It was the sergeant who spoke, and Duncan found the question strangely disturbing.

“I don’t know,” he said lamely. “ Franks seemed to take a delight in annoying them, but there was a lot of conversation I didn’t understand. I hadn’t met them before, you see, so it was difficult to gauge their reactions. There was some wrangling about lists. That seemed incomprehensible to me.”

“Yesterday afternoon,” the inspector said, “when Greg Franks told everyone he was going to lie down, the others say that they were too interested in the seabird to notice what was going on. But you tell me that you’re not a birdwatcher, so you might have been more aware of other things. Did you go to see Greg during that time?”

“No,” Duncan James said. “ I quite forgot about him until later.”

“You didn’t notice anyone else move forward to the deck where he was sleeping?”

“No,” James said. “I’m sorry. I was reading.”

“But you did go to look for Greg when they found the rare bird?”

“Oh, yes,” James said. “ That’s when I remembered him. And the others seemed so excited by the bird. They were afraid of missing anything. So I volunteered.”

“Was everyone on the deck when you left?”