George left Jerry in the seawatching hide and walked back to the observatory. There was a pile of bags and suitcases in the entrance hall. The residents were obviously eager to leave. He felt ambiguous about going. The island was not a pleasant place to be now, but if he were to go he would lose all touch with the investigation. He saw Mark Taylor in the common room and was about to talk to him when Jasmine Carson came down the stairs. She was carrying her leather holdall. The joints of her fingers were swollen and distorted. George reached out to take the bag from her. As he took it, he wondered if there were strength enough in those hands to pull the nylon rope which had strangled Charlie, if they had the power to stab a woman. But what motive could she have? She would not be squeamish about murder, but she was a scientist. She would need to be sure that such a risk was worth taking. She cared passionately about the island. Perhaps she was unreasonably attached to it. But she knew Charlie. His enthusiasms came and went like the tide. It was only through Paul Derbyshire’s persistence that Charlie’s dream of buying the island had become a reality. George was not convinced that, even if Charlie had lived, the island would ever have been sold, and he credited Jasmine Carson with the sense to realize that too.

She thanked him, ungraciously, for carrying her case, and they stood together by the pile of luggage.

“This is a bad business,” she said. “ Nicholas could be an aggressive young man, but he was always completely honest. And a very good worker. It’s all very upsetting. I know that you have faith in the police, but I suppose that there is no possibility that there could be a mistake?”

She could have been in the staff room, discussing some policy decision by the board of governors.

He hesitated, then unconsciously adopted the same tone. “ I think,” he said, “that there may have been an error of judgement.”

“I see,” she said. “In a way I’m disappointed. I had hoped that perhaps the whole matter was over, but of course that’s not the right attitude at all. We must get it right. Even if the police can’t manage to. My offer of help still stands, then.” She turned stiffly and walked slowly back up the stairs.

He went into the common room. Mark Taylor was sitting by the fire, absorbed in his own unhappiness. He still had an adolescent’s lack of defences. His clowning was natural, not a barrier against pain. Palmer-Jones sat beside him.

“Where were you last night when Nick started screaming?” he asked.

“In the bathroom.”

“That’s not true, you know. It can’t be. You told Nick that you’d gone to the bathroom, but you came along the corridor behind me when we heard the screams, as if you’d just come out of your bedroom, or from the stairs. The bathroom is further down the corridor, past Pamela’s bedroom. So where were you?”