“He must be right,” said Mma Makutsi. “But I am not sure that we will ever find this man. He is too smart. He is not a man to be caught all that easily.”

“But we are smart too,” said Mma Ramotswe. “There are two smart ladies after him, and he is just one man. No man will escape in such circumstances.”

Mma Makutsi still looked doubtful. “I hope that you’re right, Mma,” she said.

“I am,” said Mma Ramotswe simply. And with that conclusion she stood up and began to gather her things together. “I can take you home,” she said. “I am going that way.”

They locked the office behind them and made their way round to the place where the tiny white van awaited them under its acacia tree. Mma Makutsi got into the passenger seat, next to Mma Ramotswe, who strapped herself in and started the engine. As she did so, Mma Makutsi suddenly grabbed her arm and pointed to something that was happening outside the garage.

A large, silver-coloured car, a Mercedes-Benz, had drawn up at the road side. The windows of this vehicle were slightly tinted, but a woman could be made out at the driving wheel. No sooner had she stopped, than Charlie, the older apprentice, appeared from the front of the garage, sauntered across the ground between the garage and the road, and casually climbed into the passenger seat of the expensive car.

Mma Ramotswe looked at Mma Makutsi. They were both clearly thinking the same thing; Charlie had produced a roll of notes that morning, and Mma Makutsi had quite astutely suggested that he was seeing a rich woman. Well, here was a rich woman in a rich woman’s car, and there was Charlie setting off with her at the end of work. There was only one interpretation that anybody could put on that.

“Well,” exclaimed Mma Makutsi. “That’s that then.”

Mma Ramotswe stared in fascination. “Who would have thought that that silly boy could take up with a woman like that? Who would have thought it?”

“There are some women like that,” said Mma Makutsi, a strong note of disapproval in her voice. “They call them cradle-snatchers. That is because they take young men away from girls of their own age. They steal these boys away.”

“So that woman is a cradle-snatcher,” said Mma Ramotswe. “That is very interesting.” She paused, and then turned to Mma Makutsi. “I think that we shall have to come back on duty right now,” she said. “I think that we should follow that car, just to see where they go.”

“That’s a very good idea,” said Mma Makutsi. “I do not mind being back on duty.”

The opulent silver car set off towards town, and as it did so the tiny white van swung out from the side of the garage and set off behind the other car, but at a respectable distance. For a powerful car, the Mercedes-Benz was being driven slowly; most Mercedes-Benz drivers, Mma Ramotswe had observed, seemed to be in a hurry to get somewhere, but this one, this woman of whom they had had only the briefest glimpse, seemed to be content to amble along.