Mr Polopetsi shook his head. “He is a very kind man,” he said. “I do not think that he wants to tell me. But I think that this thing has happened anyway. I think that I shall have to go soon. Maybe tomorrow. I do not know.”

Mma Ramotswe rose to her feet. “We will go and speak to him,” she said. “You come with me, Rra.”

Mr Polopetsi raised a hand. “No, Mma. Please, no. I do not want to make a fuss.”

But Mma Ramotswe had brushed aside his objections and had ushered him out of the office and into the garage, where Mr J.L.B. Matekoni was standing over a handsome red car, deep in thought, contemplating its exposed engine.

“These people who make these cars are trying to make our lives difficult,” he said. “They put in all these computers and what are we to do when they go wrong? They are trying to make cars into space ships, that is what they are doing. But we do not need space ships here in Botswana. We need good cars with engines that do not mind the dust. That is what we need.”

“You should write to the people who make these cars,” said Mma Ramotswe. “You could tell them.”

“They would not listen to me,” said Mr J.L.B. Matekoni. “I am just one man. I am just Mr J.L.B. Matekoni of Tlokweng Road Speedy Motors. They would look at my letter in Japan or America and say, ‘Who is this Mr J.L.B. Matekoni? Do we know him? What is he writing to us about?’ And then they will throw my letter in the bin. That is what would happen. I am not important.”

“You are,” said Mma Ramotswe. “You are very important. You are the best mechanic in Botswana.”

“Yes,” said Mr Polopetsi. “That is true, Rra. You are the very best mechanic. I have been proud to work with you.”

Mr J.L.B. Matekoni turned and looked at them, first at Mma Ramotswe, and then at Mr Polopetsi.

“You are a good mechanic too, Rra,” he said to Mr Polopetsi. “I have seen the way you handle an engine. You respect machinery. That comes from having worked in the hospital. You are like a doctor dealing with a patient.”

Mma Ramotswe glanced at Mr Polopetsi, and then she addressed Mr J.L.B. Matekoni. “And he is a good detective too,” she said. “He is the one who followed the tracks of the van. That was a fine piece of detective work. We could use him from time to time, as a sort of assistant. Maybe he could be an assistant-assistant detective to Mma Makutsi. She would like that.”

Mr J.L.B. Matekoni looked thoughtful. “Yes,” he said. “That would be a good idea.” He paused, and frowned. “You did not think that your job was over, did you, Rra? Just because Charlie has come back?”