Mr J.L.B. Matekoni stroked his chin. “I do not know if he really existed,” he said. “I think that he was just in a book.”

Motholeli looked to Mma Ramotswe for clarification. “Maybe,” said Mma Ramotswe. “Perhaps.”

“He is from a book,” said Puso suddenly. “My teacher told us about him. She said that he went to a waterfall and fell over the edge. She said that is what sometimes happens to detectives.”

Mma Ramotswe looked thoughtful. “I have never been to the Victoria Falls,” she said.

“If you fell over the Victoria Falls,” said Mr J.L.B. Matekoni cheerfully, “I do not think that you would drown. You are too traditionally built for that. You would float over and bounce up at the bottom like a big rubber ball. You would not be hurt.”

The children laughed, and Mma Ramotswe smiled, at least for a moment. Then her smile faded. She normally paid no attention to any references to her traditional build—indeed, she was proud of it and would mention it herself. But now, it seemed to her, rather too many people were drawing attention to it. There had been that remark from Mr Polopetsi, an ill-considered, casual remark it is true, but still a suggestion that lions would like to eat her because she was large and juicy. And then the nurse had said that she should watch her blood pressure and that one way to do this was to go on a diet. And now here was Mr J.L.B. Matekoni himself suggesting that she looked like a round rubber ball and the children laughing at the idea (and presumably agreeing).