“No, just acquaintances I had met through Tom.”

“How did Tom get on with the other staff in the hotel?” She shrugged.

“I think that they thought he was mad. But most people think that twitchers are mad. He used to go drinking with one of the chefs called Dennis. He wasn’t specially friendly with any of them.”

“Do you know anything about his conviction for possession of cannabis?”

There was a slight hesitation before she shook her head.

“No, he never talked about it.”

It was obvious then that she wanted them to go. She began to talk about Barnaby’s bedtime and to collect together the tea things.

George stayed, refusing to take these hints, even when Barnaby began to cry in a tired, bad-tempered way. He felt oddly dissatisfied. He knew that there was an important question still to be asked, but the essence of it eluded him. He had come close to it at one point, but his attention had wandered, so that he could not focus on it, could not form it precisely. Yet, still he could not take the decision to go. Molly finally dragged him away. He felt like a stubborn, ill-tempered child as she said goodbye to Sally. She almost seemed to be apologizing for his churlish behaviour. In the car he could sense her anger.

“What’s the matter, my dear?” he asked in a voice which was meant to sound conciliatory, but sounded only tired and a little pompous.

“Why did you treat her like that? You treated her like a suspect.”

“She is a suspect.”

“But the anonymous letters … Surely they clear her of suspicion.”

“Do they? It seems odd that the first letter arrived on the day of Tom’s death. Nobody but Sally knew that he planned to be on the marsh early. It was unusual for him to go birdwatching before work and he doesn’t seem to have discussed it with anyone else. If the letter was conjured out of the same sense of hatred as the murder, then the person who committed both acts must have had the gift of second sight. I’d guess that the letter was posted on the Thursday before he died. The postmark was blurred, but it only had a second-class stamp. I doubt if Tom himself knew on Thursday that he would go out to the marsh on Saturday.”

“Are you suggesting that Sally sent the letters to herself? Because she wouldn’t have known either. He didn’t phone her until Friday night. Anyway, why should she draw attention to herself?”

“In the hope that people would react in just the way that you’ve done.”

George carefully took her hand.

“I liked her too,” he said. He paused, and for the first time that afternoon his thoughts cleared. “Unless the letter-writer guessed that Tom would be out on the marsh early Saturday morning—and someone who knew him well and had seen the weather forecast could have guessed—the letters and the murder must be completely separate. That is possible, but it would be a very strange coincidence.”