“He stopped by a couple of weeks ago,” continued Mma Potokwane. “He sat there—in the chair you’re on—and asked me whether I was financially secure.”

Mma Ramotswe frowned. “How strange.”

“Yes, I thought so. So I told him that I got a good salary here and that my husband was doing reasonably well. I said that we were far from being rich, but we did not want for anything.” She paused. “Mind you, I wish we could afford a more reliable car, but then who doesn’t wish for that? Can you name one single person who doesn’t want a more reliable car?”

Mma Ramotswe laughed. “I’m happy with my van. It is very old…”

“But very reliable, Mma. I have never seen it break down—ever.”

“No, it does not break down. It just goes on and on. Mr. J.L.B. Matekoni would like me to get rid of it.”

“You couldn’t do that. It would be like getting rid of your aunt. You cannot get rid of these important things just like that.”

“So what was Mr. Polopetsi driving at?” asked Mma Ramotswe.

Mma Potokwane stared out of the window. Somewhere outside a child was crying, and her matron’s antennae had responded. But then the child stopped, and she moved her gaze to Mma Ramotswe.

“He told me that he had become a member of some sort of investment club,” she said. “He said that it was called the Fat Cattle Club and it offered very good returns. He said that the returns were, in fact, better than anything you could get from the banks or the insurance companies. He said that if I had a spare ten thousand pula he could arrange for me to join this club and get—and this was the part that astonished me—twenty-five per cent return on the money I put in.”

Mma Ramotswe’s astonishment showed. “Twenty-five per cent! That’s impossible, Mma.”

“Not with this scheme,” said Mma Potokwane. “At least, not according to Mr. Polopetsi. He said that he’s already drawn his twenty-five per cent profit—and he’s only been in the club for a few months. He said that an early pay-out was the reward you got for recruiting new members.”

Mma Ramotswe asked what the Fat Cattle Club did. She imagined that it was something to do with the buying and selling of cattle—a popular activity in Botswana and one that her own father, Obed Ramotswe, had excelled in.

“This Fat Cattle Club,” Mma Potokwane explained, “buys cattle from the drought areas in the north. Then it brings them down to a place near Lobatse and feeds them up until they are ready to sell. That’s how it makes its profits.”

“But twenty-five per cent?” said Mma Ramotswe. “You can’t make twenty-five per cent just by fattening cattle. You have the cost of the feed—cattle don’t get fat on air.”