“I heard on the local radio news that Nicholas Mardle has been arrested,” he said. He made no attempt to disguise his interest. “Do you know what’s likely to happen now? I suppose that the police have closed their investigation.”

“I suppose that they have.”

“And then poor Pamela. She was my niece, of course. Terrible business.”

“Yes,” George said seriously. “ It was quite terrible.”

“I suppose that there’s nothing that we can do to limit the publicity? For the sake of her children, you know … And my father. He’s a very old man.”

“I’m afraid not,” George said. “ Nicholas is not a juvenile you see, so the case must be held in open court. Of course if he pleads guilty it will all be over quickly.”

“Do you think that he’ll plead guilty?”

“No, I don’t.”

“Oh well, I suppose that the business will survive it.” He hesitated, then said: “ There’s no question that the boy did commit the murders, I suppose? It’s not some trick of the police to give the real culprit a false sense of security?”

Ernest spoke in the same tone of detached interest. George could not tell how important the answer would be to him. He spoke lightly.

“I think you’ve been reading too many novels, Mr. Todd. The police aren’t allowed to arrest innocent men, not knowingly.”

“Ah well, you never know.” He was pleased all the same by the answer. He made polite excuses to leave.

Laurence suddenly came to life. He muttered that he, too, must go out. He had to go through the accounts at the shop. Without Mardle there had been serious discrepancies. Suddenly George found himself alone with the secretary in the outer office. She smiled at him, but seemed bemused by her employers’ disappearance.

“Oh dear,” George said. “ There was one more question I had to ask Mr. Todd. Perhaps you could help me?”

“Of course sir, I’d be glad to help.” She seemed more relaxed, more inclined to chat with both her employers away from the office, and continued: “ I went to the island once, on a field trip. Do you know Miss Carson?”

“Jasmine Carson?” George said. “ Yes. She’s a member of the observatory.”

“She was my biology teacher. I still bump into her sometimes. She likes to keep in touch with her old girls. But how can I help you?”

“I believe that you had a visitor a week ago last Friday. Friday the seventh.”

“I explained that Mr. Charles Todd hadn’t visited us for some months.”

“So you did. But I’m not talking about Charlie. Did anyone else come into the office that day?”

She was about to question his right to ask, but the habit of politeness was too strong.

“Yes, someone did call in, but I’m afraid I don’t know who it was. She refused to give her name. She saw Mr. Ernest.”

“Could you describe her?”

The secretary had obviously been offended by the strange caller. “She was in her late twenties, I suppose. She might have been a bit older. Tall and thin, with long, dark, curly hair. A bit scruffy.”