“He’ll be here somewhere,” Rob said at his most irritatingly flippant. “On the last trip I did, Keith Vinicombe fell asleep in a lifeboat, and we thought we’d lost him overboard.”

He stretched again.

Molly and George helped Duncan James to look for Greg. At first it was a chore, and they thought it would soon be over. They searched the boat from end to end, growing more bewildered and disturbed as they failed to find any sign of Greg Franks. It was as if he had never existed. His clothes, his bag, his binoculars, and the telescope had all disappeared. As he was rooting fruitlessly through a storage space in the bulkhead, George remembered suddenly a nightmare which had recurred when his first son was a baby. He dreamed he had taken the boy in his pram into a strange and busy town, then left him on a street corner and forgotten about him. Later, when he returned in panic to look for the pram, all sign of it and the baby had gone, and he ran helplessly round the streets in a futile search. The search for Greg Franks had the same nightmare quality. Finally they called the others to help them, and they chased round the boat in a frenzy, calling Greg’s name, angry because they felt he must be playing some elaborate practical joke.

Rose Pengelly found Greg, and she had stopped looking for him. Throughout the search she was calmer than the others. She searched the cabins carefully but without their panic. Then Matilda, who had been sleeping in a carrycot in the saloon, woke up, and Rose said she would have to attend to her. She would need changing. She would be hungry. She took the baby to the deck at the stern of the boat. It was midafternoon, and that was the only part of the boat still in sunlight. Louis was already steering the boat back towards land. She put a rug on the deck and sat there, feeding the baby, quite content it seemed, despite the disappearance of the young man, quite self-contained.

When she screamed, Louis got to her first. He could not tell what was wrong with her. Her mouth was open with horror, but she could not speak. He could see nothing out of order. The baby was still feeding with muffled murmurs of delight. The rubby dubby bag, now almost empty, still attracted a stream of petrels and gulls.

Rose pointed to the rubby dubby bag.

“Look,” she said at last.