Then Mma Ramotswe laughed. “Don’t worry,” she said. “I know what you mean, Mma Makutsi. Mr J.L.B. Matekoni is maybe not the most fashionable man in town, but he is one of the best men there is. You could trust him with anything. He would never let you down. And I know he would never have any secrets from me. That is very important.”

Grateful for her employer’s understanding, Mma Makutsi was quick to agree.

‘That is by far the best sort of man,” she said. “If I am ever lucky enough to find a man like that, I hope he asks me to marry him.”

She glanced down at her shoes again, and they met her stare. Shoes are realists, she thought, and they seemed to be saying: No chance. Sorry, but no chance.

“Well,” said Mma Ramotswe. “Let’s leave the subject of men in general and get back to Mr Badule. What do you think? Mr Andersen’s book says that you must have a working supposition. You must set out to prove or disprove something. We have agreed that Mma Badule sounds bored, but do you think that there is more to it than that?”

Mma Makutsi frowned. “I think that there is something going on. She is getting money from somewhere, which means she is getting it from a man. She is paying the school fees herself with the money she has saved up.”

Mma Ramotswe agreed. “So all you have to do is to follow her one day and see where she goes. She should lead you straight to this other man. Then you see how long she stays there, and you speak to the housemaid. Give her one hundred pula, and she will tell you the full story. Maids like to speak about the things that go on in their employers’ houses. The employers often think that maids cannot hear, or see, even. They ignore them. And then, one day, they realise that the maid has been hearing and seeing all their secrets and is bursting to talk to the first person who asks her. That maid will tell you everything. You just see. Then you tell Mr Badule.”

“That is the bit that I will not like,” said Mma Makutsi. “All the rest I don’t mind, but telling this poor man about this bad wife of his will not be easy.”

Mma Ramotswe was reassuring. “Don’t worry. Almost every time we detectives have to tell something like that to a client, the client already knows. We just provide the proof they are looking for. They know everything. We never tell them anything new.”

“Even so,” said Mma Makutsi. “Poor man. Poor man.”

“Maybe,” Mma Ramotswe added. “But remember, that for every cheating wife in Botswana, there are five hundred and fifty cheating husbands.”

Mma Makutsi whistled. “That is an amazing figure,” she said. “Where did you read that?”