I drove to Truro the next morning with Jamie beside me, silent and pale. He confessed in the car that he had sold it, ashamed, because his mother’s boiler had broken and the family could not afford to fix it. Mr. Dunstan met us at the door of the shop. He locked it behind us, turned the sign to closed, and led us to a small back room.

On a velvet cloth lay Tom’s watch with its back case removed. Under a magnifying lamp, I could see engraved letters on the inside of the case. “Arthur, if you find this, forgive me.” Mr. Dunstan said quietly, “Mr. Penhallow, this is a rare Rolex Submariner from 1964. It is worth more than thirty thousand pounds. And there is a tiny folded paper beneath the movement.”