“She was heading out to Molepolole,” went on Mr J.L.B. Matekoni, “and she remembered that she had not fed the chickens back in Gaborone. So she decided that she would go straight back by changing into reverse. You can imagine what that did to the gearbox. And suddenly everybody was talking about it. They assumed that I had told people, but I hadn’t. A mechanic should be like a priest. He should not talk about what he sees.”

Mma Ramotswe agreed. She appreciated the value of confidentiality, and she admired Mr J.L.B. Matekoni for understanding this too. There were far too many loose-tongued people about. But these were general observations, and there were more pressing matters still to be discussed, and so she brought the conversation round to the subject which had started the whole debate.

“So they are talking about our engagement,” she said. “Some of them even asked to see the ring you had bought me.” She glanced at Mr J.L.B. Matekoni before continuing. “So I told them that you hadn’t bought it yet but that I’m sure that you would be buying it soon.”

She held her breath. Mr J.L.B. Matekoni was looking at the ground, as he often did when he felt uncertain.

“A ring?” he said at last, his voice strained. “What kind of ring?”

Mma Ramotswe watched him carefully. One had to be circumspect with men, when discussing such matters. They had very little understanding of them, of course, but one had to be careful not to alarm them. There was no point in doing that. She decided to be direct. Mr J.L.B. Matekoni would spot subterfuge and it would not help.

“A diamond ring,” she said. “That is what engaged ladies are wearing these days. It is the modern thing to do.”

Mr J.L.B. Matekoni continued to look glumly at the ground.

“Diamonds?” he said weakly. “Are you sure this is the most modern thing?”

“Yes,” said Mma Ramotswe firmly. “All engaged ladies in modern circles receive diamond rings these days. It is a sign that they are appreciated.”

Mr J.L.B. Matekoni looked up sharply. If this was true—and it very much accorded with what Mma Potokwane had told him—then he would have no alternative but to buy a diamond ring. He would not wish Mma Ramotswe to imagine that she was not appreciated. He appreciated her greatly; he was immensely, humbly grateful to her for agreeing to marry him, and if a diamond were necessary to announce that to the world, then that was a small price to pay. He halted as the word “price” crossed his mind, recalling the alarming figures which had been quoted over tea at the orphan farm.

“These diamonds are very expensive,” he ventured. “I hope that I shall have enough money.”

“But of course you will,” said Mma Ramotswe. “They have some very inexpensive ones. Or you can get terms …”

Mr J.L.B. Matekoni perked up. “I thought that they cost thousands and thousands of pula,” he said. “Maybe fifty thousand pula.”