He got up slowly as if he wished to emphasize his point, went to his rucksack and brought out a polythene bag with two candles and a box of matches. He lit one of the candles and stuck it on to the table. They could see that Molly was fast asleep now, her head on her arms like a child at its desk. George pulled the typewritten police report out of the large pocket in his coat and read it closely. He explained to Rob what it was, but refused to give it to him to read.

“I don’t think that would be quite ethical,” he said. “I’ve broken enough rules to get hold of it. Anyway it probably comes under the Official Secrets Act and I don’t want to get you into trouble. I’ll give you the gist.

“He was killed by a number of blows to the head, the back of the head and the neck. The weapon is described as a smooth, heavy object. Probably cylindrical. I haven’t got the medical report, so I don’t know why they say that.”

Rob interrupted excitedly: “Smooth and cylindrical. That could be a telescope.” It had become something of a game.

“It’s too early to say, I think. It could have been any sort of club, metal piping, even a sturdy walking stick. They don’t think that Tom was killed exactly where he was found, but there are no cuts or abrasions to suggest that he was dragged along the ground.”

Rob was quite absorbed.

“If he was killed at any distance from the marsh, I don’t know how the murderer could have moved the body to the pool. It’s a long way from the road. I suppose that it might be possible to drive up the marsh track in a car—I’ve seen it done with a Land Rover. But then the body would have to be carried into the water. It sounds very risky.”

“The report doesn’t mention tyre tracks at all. The police would have looked for them. There must have been dozens of people tramping up and down it all day, so that doesn’t mean anything. I think that it would have been possible for two people to move him, carrying the body between them, but then, as you say, that would have been conspicuous. Of course it was extremely foggy.

“They think that he died very early in the morning—again I’ve no medical evidence for that, but I think we can accept the information. The forensic experts have enormous skill and are usually frighteningly accurate. He was certainly in the water for at least ten hours. He left the hotel at five forty, so he must have been killed between then and nine a. m., but the report places the probable time of death at between five forty and seven thirty.

“The police seem to be concentrating their efforts on the hotel where he worked and are making inquiries locally. By the time they were called, many of the twitchers would have left the village. It was the day of the bimaculated lark, of course. I got the impression that a considerable number of people gave up and went elsewhere in the early afternoon, when the fog showed no sign of clearing. Any birder still in Rushy would have been in the White Lodge park. Apparently the police have started to compile a list of birdwatchers, and everyone will be questioned. Even you and I, I presume. It will be interesting to see how soon they get round to us.”