Mma Ramotswe cleared her throat.

“Mma Makutsi,” she began. “I have been thinking about the future.”

Mma Makutsi, who had finished her rearranging of the filing cabinet, had made them both a cup of bush tea and was settling down to the half-hour break that she usually took at eleven in the morning. She had started to read a magazine—an old copy of the National Geographic—which her cousin, a teacher, had lent her.

‘The future? Yes, that is always interesting. But not as interesting as the past, I think. There is a very good article in this magazine, Mma Ramotswe,’ she said. ‘I will lend it to you after I have finished reading it. It is all about our ancestors up in East Africa. There is a Dr Leakey there. He is a very famous doctor of bones.’

“Doctor of bones?” Mma Ramotswe was puzzled. Mma Makutsi expressed herself very well—both in English and Setswana—but occasionally she used rather unusual expressions. What was a doctor of bones? It sounded rather like a witchdoctor, but surely one could not describe Dr Leakey as a witchdoctor?

“Yes,” said Mma Makutsi. “He knows all about very old bones. He digs them up and tells us about our past. Here, look at this one.”

She held up a picture, printed across two pages. Mma Ramotswe squinted to make it out. Her eyes were not what they once were, she had noticed, and she feared that sooner or later she would end up like Mma Makutsi, with her extraordinary, large glasses.

“Is that Dr Leakey?”

Mma Makutsi nodded. “Yes, Mma,” she said, “that is him. He is holding a skull which belonged to a very early person. This person lived a long time ago and is very late.”

Mma Ramotswe found herself being drawn in. “And this very late person,” she said. “Who was he?”

“The magazine says that he was a person when there were very few people about,” explained Mma Makutsi. “We all lived in East Africa then.”

“Everybody?”

“Yes. Everybody. My people. Your people. All people. We all come from the same small group of ancestors. Dr Leakey has proved that.”

Mma Ramotswe was thoughtful. “So we are all brothers and sisters, in a sense?”

“We are,” said Mma Makutsi. “We are all the same people. Eskimos, Russians, Nigerians. They are the same as us. Same blood. Same DNA.”

“DNA?” asked Mma Ramotswe. “What is that?”

“It is something which God used to make people,” explained Mma Makutsi. “We are all made up of DNA and water.”

Mma Ramotswe considered the implications of these revelations for a moment. She had no views on Eskimos and Russians, but Nigerians were a different matter. But Mma Makutsi was right, she reflected: if universal brotherhood—and sisterhood—meant anything, it would have to embrace the Nigerians as well.

“If people knew this,” she said, “if they knew that we were all from the same family, they be kinder to one another, do you think?”

Mma Makutsi put down the magazine. “I’m sure they would,” she said. “If they knew that, then they would find it very difficult to do unkind things to others. They might even want to help them a bit more.”