“I think I may have some good news for you about the letters,” he said. “ I know who wrote them.”

Molly, who seemed to have been forgotten by both adults, watched and was puzzled by Sally’s reaction. She thinks she knows who wrote them, she thought. She’s afraid she knows who wrote them, and she doesn’t want anyone else to know.

“Is it anyone I know?” Sally asked.

She waited for an answer, Molly thought, like a child waiting for an exam result.

“I don’t think so,” George said. “ It was Bernard Cranshaw. He never liked Tom.”

Her relief was controlled but very obvious to Molly, who was watching for it. Sally relaxed and, perhaps in an attempt to hide her relief, bent to build Barnaby’s tower once more.

When she said nothing, George continued talking.

“I don’t know what to do with the information. It’s your decision. I’m convinced that Cranshaw wrote the letters to you. I feel that I should tell the police about it, but if I do that, they’ll want to talk to you; and if Cranshaw doesn’t plead guilty you’ll probably have to appear in court as a witness. On the other hand I could talk to him, persuade him to see a doctor, and only call in the police if the letters start again. As I said, it’s your decision.”

“But won’t you have to tell the police? Doesn’t that mean that he killed Tom?” There was something hopeful, almost pleading in her voice.

“I don’t think so,” George said. “I think the letters were a coincidence. The later letters mention Tom’s death. But the first, which arrived on the day he was killed, says nothing about it. I can’t see how Tom’s death could have been planned far enough in advance to allow the first letter to reach you on the Saturday morning, even if it was posted on the morning before. Bernard Cranshaw may have killed your boyfriend, but unless the police have more information than I do, in which case they would already have charged him, they won’t be able to prove it.”

Now the subject of the letters seemed hardly to interest her. “Don’t tell the police then,” she said. “I don’t think I could face any more questions.”

There was another silence, broken only by Barnaby’s noisy attempt to climb on to Molly’s knee. Sally suddenly seemed to become aware again of her duty as hostess and said politely, making conversation:

“Thank you for giving me a lift home last night. I hope that you didn’t miss too much of the party.”

“Not at all,” George said. “Are you feeling better?”

“Oh, I’m fine now. I feel very guilty about having dragged you away.”

“In the circumstances, perhaps it’s as well that you did.”

“In the circumstances?” The routine politeness had disappeared. She sensed from his tone that something had happened at the party in her absence and she was frightened.

“I’m sure that you know that under the wooden experimental windmill in the car park at Ella’s, there’s an old disused well. When I returned to the party after bringing you home, I heard a noise from the well. One of the younger twitchers, Adam Anderson, was trapped in the well shaft, on a metal grille which half covers the water at the bottom, he had been there for some hours and, of course, he was very frightened. He says that he fell. Molly and I had received the impression that Adam knew something about Tom’s death, something he was too frightened to talk about. I don’t suppose you know anything about it? You seemed very anxious to leave the party in a hurry last night.”