He left them standing in the marsh, wondering how best to move the body. Furious with the defective logic, their inability to think clearly, his own ineffectiveness, he walked down the island and banged on the door at Unsta. He was determined now to finish the thing quickly. He had to prove to himself and to the police now that he could do it. He had wasted five days. Sarah came to the door. It was still early, but Jim was already out.

“Robert’s been murdered,” he said.

She felt betrayed. The evening before had promised endless happiness. The promise was already broken.

“The police are trying to persuade themselves that it was another accident,” he said. “It’s just intellectual laziness. They’ll realize that soon. I want to ask some questions before they start taking statements. Will you come with me?”

He was compelling. He made her feel that it was her duty to go with him. He seemed to have a new energy and power. When they walked she found it hard to keep up with him. Yet he had had no sleep.

He was unsure why he was so reluctant to ask the questions alone. When he was working as a civil servant with the Home Office, there had been no opportunity to share responsibility. His independence had been the aspect of the work he had enjoyed most. Perhaps he had become too accustomed to sharing problems with Molly. He knew that an extra perspective would be invaluable.

“I wouldn’t want to put you in an awkward position.”

“No. I’d like to come with you. I think I should.”

His power and authority attracted her.

“I thought that we’d start at Kell and move south.”

“I understood that visitors weren’t welcomed at Kell.”

His sudden burst of anger surprised her: “ We won’t behave like the foolish policemen,” he said. “We’re doing the thing properly. If you prefer you can opt out now.”

“No. I want to come.”

He talked continuously as they walked, communicating his thoughts to her, and ordering his ideas, so that he would know just what questions to ask.

“Robert found out Mary’s secret,” he said. “ He saw or heard something, or he worked it out for himself. He saw the person talking to Sylvia Drysdale, but that might mean nothing. We must remember it, but not give it undue importance. If we knew the secret, we would know the identity of the murderer. It’s the essence of the case. But several people here seem to have a secret. Maggie thinks that Alec and Sylvia were having an affair. Elspeth Dance is frightened of something. She was afraid that her son would talk to me. Kenneth and Annie are trying to protect her. Jonathan says that Sylvia flirted with anyone who would give her attention, so she might have been involved with more than one man.”