Everything, all these great things, had happened so far away-or so it seemed to her at the time. The world was made to sound as if it belonged to other people-to those who lived in distant countries that were so different from Botswana; that was before people had learned to assert that the world was theirs too, that what happened in Botswana was every bit as important, and valuable, as what happened anywhere else.

But where had that doctor grown the penicillin that was to save so many lives? In his garden? She thought not. It was in his laboratory somewhere, perhaps in a cup of tea that he left on a windowsill, as Mr. J.L.B. Matekoni had done once and Mma Ramotswe had discovered it, months later, when the half-finished liquid had turned to green mould.

“In a cup of tea,” she said hesitantly. “Maybe. Or in a saucer, perhaps.”

“That is very interesting, Mma,” said Mma Makutsi briskly. “But I have been thinking about a more efficient way of making the tea in this office. I am not interested in making penicillin or inventing anything.”

Mma Ramotswe nodded encouragingly. “It is a good thing to be efficient,” she said.

Mma Makutsi seized her chance. “So why don’t we use the big teapot to make the ordinary tea,” she said. “There are always more people wanting ordinary tea-Mr. Polopetsi, for instance, and Charlie and Fanwell. If we made the ordinary tea in that big pot, then I would not have to make a second pot.” She paused. “And it would make no difference to your red bush tea, Mma. You would still have more than enough.”

For a few moments Mma Ramotswe said nothing. I’ve offended her, thought Mma Makutsi. I shouldn’t have spoken about this. But then Mma Ramotswe, who had been looking out of the window, as if pondering this casually lobbed bombshell, turned to Mma Makutsi and smiled. “That is a very good idea, Mma,” she said. “Every business needs new ideas, and that is one. Change the pots next time you make tea.” She paused. “I do not mind having the smaller pot. Not at all.” And then, after a further pause, “Even if I have always loved that big teapot.”