The letter concluded, she attached a twenty-pula note to it with a pin, addressed the envelope and sealed it. That was her daughterly duty done for the week, and she smiled to herself as she imagined her father opening his small metal postal box (which she paid for) and his pleasure in receiving her letter. She had been told that he would read each letter again and again, extracting new significance each time from each phrase and each sentence. Then he would show it to his friends, the other old men, or read it to those who could not read, and they would talk about it for hours.

By the time the letter was finished, and the quick telephone call made, she heard Mr J.L.B. Matekoni’s truck arriving outside. This truck always made more noise than any other vehicle, which was caused by its engine being different from the engines of other trucks. That was what Mr J.L.B. Matekoni had said, and he was undoubtedly right. He explained that the engine had been badly looked after by the previous owner and it had been impossible to undo the damage altogether. But it remained a good truck at heart; like a faithful beast of burden that has been maltreated by an owner but which has never lost its faith in man. And hard on the heels of the truck came the tiny white van, which drew to a halt in its parking place under the acacia tree at the side of the garage.

Mma Ramotswe and Mma Makutsi had already opened the morning mail by the time that the apprentices arrived. The older apprentice, Charlie, sauntered into their office, whistling a tune, and smiling cheekily at the two women.

“You look pleased with yourself,” said Mma Ramotswe. “Have you won a big prize or something?”

The apprentice laughed. “Wouldn’t you like to know, Mma? Just wouldn’t you like to know?”

Mma Ramotswe exchanged glances with Mma Makutsi. “I hope you haven’t come to borrow money,” she said. “I am happy to help you, but you really should pay me back that fifty pula you borrowed at the beginning of the month.”

The apprentice affected injured innocence. “Ow! Why do you think I should need to borrow money, Mma? Do I look like somebody who needs to borrow money? I do not, I think. In fact, I was just coming in to pay you back. Here. Look.”

He reached into his pocket and took out a small roll of notes, from which he peeled off fifty pula. “There,” he said. “That is fifty pula, is it not? And that is what I owe you. I am giving it back right now.”

Mma Ramotswe took the money and slipped it into her drawer. “You seem to have a lot of money there. Where did you get it? Have you robbed a bank?”

The apprentice laughed. “I would never rob a bank. That is just for fools. If you rob a bank, then the police will surely catch you. That is always true. So don’t rob a bank, Mma!”