George answered gently. “She did love him, you know. All the secrecy was on his behalf, not her own. She only flirted with Alec so that you wouldn’t think of looking elsewhere for someone to associate her with. She knew what a reputation she has.”

“It was James who shot at you, when we were out ringing the swans,” Sarah said.

“Yes. It was a foolish thing to do. I think by that time he was insane with fear and worry. He must have heard that I’d gone out to Baltasay on the plane. Perhaps he thought that I’d given up the investigation and gone home. Then I turned up on the Ruth Isabella. With Sylvia. I don’t know who he was trying to hit then, up on the hill—Sylvia or me. Perhaps he was trying to frighten her into keeping quiet about their relationship or perhaps he was trying to frighten me away altogether. By that time I don’t think he knew what he was doing. I don’t think that he can have meant to kill either of us. He could have done that easily enough if he’d tried. After all, when I wandered into the lighthouse, I had a gentle tap on the head, not a bellyful of shot.”

“You knew who it was at that time?” asked Sarah.

“Yes, though I had only worked it out that evening, as we were getting ready to ring the swans. Before that I thought that Mary’s secret was quite different.”

“Something to do with Elspeth?”

“Yes. But it turned out to be quite irrelevant. So I went back to the scarf. Whoever had been talking to Sylvia had dropped the scarf. From her attitude it was most likely to be a man, a lover. There weren’t that many candidates. If it had been Alec, he would have been rather proud to let the island know what was going on. It had to be someone of sufficient standing for it to matter desperately if the secret came out. That meant Sandy, Kenneth Dance, or James. Then I remembered Melissa’s extreme reaction when I showed her the scarf at Kell, and James’ attitude to Sylvia—he emphasized over and over again how much he disapproved of her—and the thing became clear. I was certain when I realized that whoever was in the lighthouse had a key to the padlock on the door. I knew he’d been the assistant keeper there. The Northern Lights Board were most likely to choose him as a caretaker.

“I really thought that it was Melissa,” Sarah said. “All day I’ve been thinking that it was her and that James killed himself through shame or a second-hand guilt.” She looked around the room. “She was so convincing,” she said, almost apologetically. “I believed every word she said.”