The track ended in front of the lighthouse. Not many years before, three families had lived there. The light-keepers’ cottages were still there, the windows boarded up. Everything had been left—washing lines, a children’s swing in one of the gardens, a rusting wheelbarrow. It was as if the people had all left quite suddenly and mysteriously. George was reminded of other islands where the whole population had been evacuated because so few people remained. In his torchlight the lighthouse compound evoked the same sad and empty feeling. The beam of the light swung above them, regular, remote, and impersonal. It was switched on automatically now as the daylight faded. Each time it swung above their heads it illuminated the cliffs of a nearby headland. George remembered Mary and thought that it had been right to send the men and their families away. It was not a safe place for children.

The others were unloading the Land Rover with whispered giggles. Jonathan was worried that they would frighten away the swans and was trying to keep them quiet.

He and Will had thigh waders, so they would go into the water to catch the swans.

“I want to hold the torch,” Sylvia said. “ I want to work the magic on them.”

“You won’t hold it steady. Let George to it.”

“No,” she said, sulky as a child. “I want to do it.” And she was given her own way.

The pool they called Silver Water was away from the road, over moorland too boggy to take the Land Rover safely, in a dip in the hills, quite close to the edge of the cliff. To George it hardly seemed bigger than a village duckpond.

Jonathan made them switch off their torches before they started, and they stumbled and splashed through the peat bog. Sylvia and Sarah went arm in arm, giggling together, but Jonathan was taking it very seriously. They stopped just as the land rose and became drier. Jonathan wriggled forward on his stomach and peered over the rocky mound and down to the pool. The swans were there, he whispered. He could hear them. Sylvia would go down to the water one way, with the torch, and he and Will would go the other. George hoped that he would be left alone then. He had known why Robert had been killed right from the beginning. Now he knew why Mary had been murdered and the identity of the murderer could only be one of three people. If he had time, he had the facts to work the thing out. Tomorrow, he thought, it will all be over. But Jonathan would not let him sit alone. He sent George down the bank with Sylvia, saying that he did not trust her to dazzle the birds properly.