Mma Makutsi smiled. “I can go and find out just what’s going on,” she said. “Then I can look at ways of dealing with it.”

“But we know perfectly well what’s going on,” said Mma Ramotswe. “The goings-on are between him and that rich lady with the Mercedes-Benz. Anybody can tell what that’s all about. That’s what’s going on.”

Mma Makutsi agreed that this was so. But in her view there was always more beneath the surface, and they had of course seen the lady and the apprentice drive into Mr J.L.B. Matekoni’s yard. That remained something of a mystery.

“There are still some things to be looked at,” she said to Mma Ramotswe. “I have been thinking that Mr J.L.B. Matekoni and I should have a closer look. That’s what I’ve been thinking.”

“You must be careful of Mr J.L.B. Matekoni,” cautioned Mma Ramotswe. “He is a very good mechanic, but I do not think that he will be a very good detective. In fact, I am sure he will not be.”

“I shall be in charge,” said Mma Makutsi. “I shall make sure that Mr J.L.B. Matekoni comes to no harm.”

“Good,” said Mma Ramotswe. “He is the only husband I …” She stopped. She had been about to say that he was the only husband she had, but then she realised, with a feeling of dark foreboding, that this was not strictly true.

WHEN MMA MAKUTSI suggested to Mr J.L.B. Matekoni that they pay a visit to his new tenant, he looked at his watch and scratched his head.

“I have so much to do, Mma,” he said. “There is that car over there which has no brake pads left. Then there is that van which is making a noise like a donkey. There are many sick vehicles here, and I cannot leave them.”

“They are not dying,” said Mma Makutsi firmly. “They will still be here when we come back.”

Mr J.L.B. Matekoni sighed. “I do not see why we need to go to the house. They are paying their rent. The house has not been burned down.”

“But there is Charlie,” pointed out Mma Makutsi. “We should find out why he is going to your house. What if he is being sucked into some sort of criminal activity, with that fancy lady of his and that Mercedes-Benz?”