For Elspeth it happened very quickly. When she saw Matthew go in up to his waist, she laughed and called out to him not to ruin his clothes. “Saltwater,” she cried out. “Saltwater ruins things. Don’t get any wetter, Matthew. Matthew…”

Then she saw the waves cover him and she became alarmed. Matthew could swim – she knew that – but why had he decided to swim at night? Suddenly she thought of what the waitress had said that evening. Their element. The Great Whites. She screamed and waved frantically, but Matthew seemed to be ignoring her. She saw his head, bobbing in the surf, but then it disappeared and when the surf cleared it was not in the spot she had seen him in; or was that him, that darker patch in the water?

Within the space of a couple of minutes, she could see no trace of him. She advanced to the edge of the water and took a few steps into the waves; but what point was there in her going in? She could not see him; she had no idea where he was. The rips. The waitress had said there were rips.

She turned round, half panicking. Down the beach, about ten minutes away, was the restaurant with its lights and people and telephones. She started to run, stumbling in the sand, which slowed her down. She began to sob, struggling for breath. Matthew was going to drown. Her husband. She was going to lose him.

When she arrived at the restaurant she burst through the first door she found. Several people were sitting round a table, one of them the waitress who had served them earlier on.

“Left something behind?”

“My husband…”

They laughed.

But then, in a moment, they understood.

Bertie had been dreading the afternoon on which both Tofu and Olive were to come to his house. In normal circumstances he would have been pleased – Tofu may not have been the best of friends, but he was the closest thing to a friend that Bertie had. And Bertie had a sneaking admiration for Tofu, in spite of all the fibs that his friend told, his tendency to spit at people, and all his outrageous exploits; at least Tofu did the things that he wanted to do. At least Tofu didn’t have a mother breathing down his neck all the time.

There was some debate about Tofu’s mother. Tofu himself never spoke about her, but waved his hand vaguely when the subject of mothers arose. This could be interpreted as insouciance – a gesture indicating that mothers might be a problem for some, but not for him. Or it could have been intended to convey that Tofu was not sure about the precise location of his mother – the sort of gesture one makes when giving directions to a place one is not entirely familiar with: it’s somewhere over there.

Certainly Tofu’s mother had never been seen by any of the other children at the Steiner School. When Tofu was picked up at school it was always by his father, the author of well-known books on plant energy fields. And sometimes Tofu simply walked out of the school gate, announcing that he did not need to be picked up and that he was perfectly capable of catching a bus unaided. That always drew gasps of admiration from the others, except from Olive, of course, who simply narrowed her eyes in hatred and said nothing.

Olive had a variety of explanations for the apparent absence of Tofu’s mother.

“She’s in Saughton Prison,” she said. “She’s been there for years.”

Bertie doubted this. He had read about Saughton Prison in the newspapers and it had been described as a male prison. But when he pointed this out to Olive, she had been undismayed.

“That’s what you think, Bertie,” she said. “But you don’t know anything about prisons, do you? So who do you think does the cooking in Saughton Prison? Men can’t cook, can they, Mr. Smarty Pants! So they have a special room there for bad ladies and they do the cooking. So there!”

This struck the others as entirely feasible, but Bertie remained doubtful.

“I don’t think that she’s in prison,” he said. “Why would she be there anyway?”

“Murder,” said Olive.

Bertie plucked up his courage. Olive was not an easy person to argue with. “All right,” he said. “Who did she murder, Olive? You tell us if you’re so sure.”

Olive thought for a moment. She looked first at Bertie and then at the faces of the other children around them. “You’ll find out,” she said. “Just you wait. You’ll find out.” And with that she changed the subject.

The other theory about Tofu’s mother was that she had starved to death. Olive herself, ignoring the inconsistency which this idea involved with her remarks about her being in prison, had put about the notion that Tofu’s mother had starved because the whole family was vegan. “She became very thin,” she announced. “That’s what happens to vegans. They don’t last long.”

Bertie had eventually decided to ask Tofu whether he had a mother or not. He did not like the rumours that Olive was putting about and he thought that the best way of putting an end to these would be to find out the truth.

“Where’s your mother, Tofu?” he asked one day in the playground.

“At home,” said Tofu, waving a hand vaguely.

“Are you sure?” asked Bertie.

“How do I know what my mother’s doing?” Tofu snapped back. “I can’t look after her all the time.”

Bertie had dropped the topic, but it worried him. Tofu was so full of bluff and bravado, but was he really sad inside? A boy with no mother to look after him and a father who went on about nuts and broccoli? Bertie reflected on his own mother situation and wondered if he was not, in fact, fortunate in having the mother he did. What would it be like if his mother were suddenly not to be there? He had so often wished for that, but now he remembered seeing something in that small antiques store on the corner of Great King Street. One morning he had stopped and seen in the window an elaborately worked Victorian sampler mounted on a stand. “Be careful what you wish for,” it had read, and Bertie, puzzled, had drawn the message to the attention of his father.

“What does that mean, Daddy?” he asked. “Why should you be careful what you wish for?”

Stuart smiled. “They were always coming up with things like that in those days,” he said. “We used to have one of those at home. It was made by your great-grandmother, Bertie. It said, ‘Save your breath to cool your porridge.’”

“That’s very funny,” said Bertie. “Did it mean that you shouldn’t talk too much?”

“Exactly,” said Stuart, ruffling his son’s hair and thinking he could name at least one woman who might consider that. But he immediately felt disloyal and put the thought out of his mind.

“So what do they mean about being careful what you wish for?” Bertie asked.

Stuart reached for Bertie’s hand as they stood on the pavement in front of the shop. Behind them, a 23 bus lumbered up Dundas Street; above, a gull mewed and circled. He looked down at his son, at the eager face staring up at him. There were so many questions – and so many wishes. Wishes, he thought, are usually for the world to be quite different from the way it currently is, but do we really want that?

“The thing you wish for,” Stuart began, “may not be what you really want. You may think it would be nice if something happened, but then, when it happens, you may find that it’s not really what you wanted. Or you may find that things are worse.”

He looked at Bertie. What did this small boy wish for? What hopes were harboured in his brave little heart?

“What are your special wishes, Bertie?”

Bertie thought for a moment. “I thought you shouldn’t speak about wishes. I thought that if you spoke about them they wouldn’t come true.”

“Maybe you’re right,” said Stuart. “Maybe.”

“But I’d really like to join the cub scouts, Daddy.” He hesitated. “And wear a uniform.”