“But you’re so right, Rra,” said Mma Ramotswe. “And I have always wondered how you know all these things. It must be experience, I think.”

Clovis Andersen looked away. “Experience and common sense,” he said. “There are so many jobs that are just a matter of common sense. Most jobs, in fact. They look complicated, but when you look closely you’ll see that all you really need is common sense.”

Mma Ramotswe considered this. It was true that private detection involved a great deal of common sense, and undoubtedly there were many other professions in which common sense would get you by, but surely there were those where the limits of common sense would very soon be revealed—being a dentist, for example, or an airline pilot …

She toyed with the idea of pointing this out to him, but decided not to. The traditional ways of Botswana were clear about correcting a person who was senior to you, or a stranger, and on both of these counts she should not directly contradict Clovis Andersen. You did not have to remain silent, of course, if such a person was wrong, but you should be careful how you voiced your disagreement. So she simply said, “Common sense is very useful. Yes.”

There was a brief silence. Then she said, “You must have seen so many things, Rra. In your career as a detective, you must have seen so many things.”

Clovis Andersen nodded. “There are many things to be seen in this life, Mma. All one has to do is keep one’s eyes open.”

Mma Ramotswe voiced her agreement. “Oh, you are so right, Rra. The big mistake is to close your eyes. There are so many who have closed eyes. You look at them, of course, and you think that they have open eyes, but then you look more closely and you realise that although their eyes are open, there is nothing going in.”

“That’s because they aren’t looking,” said Clovis Andersen. “If you do not look, you do not see.”

“That is so true, Rra,” enthused Mma Ramotswe. “That is so true.”

He went on. “There are some people who have their eyes open and are looking, but do not see anything because they are looking for something that is not there. That can happen, I believe.”

“Oh, I believe that too, Rra,” said Mma Ramotswe. “I have always believed that—all along.”

“That is not to say there’s nothing there,” continued Clovis Andersen. “There may be something there, but because nobody’s looking for it, it won’t be seen. So we should always ask ourselves: are we looking for the right thing?”

Mma Ramotswe agreed again. “That is definitely the thing to do,” she said.