The tenth book in the No 1 Ladies Detective agency series, 2009

TRADITIONALLY BUILT PEOPLE may not look as if they are great walkers, but there was a time when Precious Ramotswe walked four miles a day. As a girl in Mochudi, all those years ago, a pupil at the school that looked down over the sprawling village below, she went to her lessons every morning on foot, joining the trickle of children that made its way up the hill, the girls in blue tunics, the boys in khaki shirts and shorts, like little soldiers. The journey from the house where she lived with her father and the older cousin who looked after her took all of an hour, except, of course, when she was lucky and managed to ride on the mule-drawn water cart that occasionally passed that way. The driver of this cart, with whom her father had worked in the gold mines as a young man, knew who she was and always slowed down to allow her to clamber up on the driver's seat beside him.

Other children would watch enviously and try to wave down the water cart. “I cannot carry all Botswana,” said the driver. “If I gave all you children a ride on my cart, then my poor mules would die. Their hearts would burst. I cannot allow that.”

“But you have Precious up there!” called out the boys. “Why is she so special?”

The driver looked at Precious and winked. “Tell them why you are special, Precious. Explain it to them.”

The young Mma Ramotswe, barely eight, was overwhelmed by embarrassment.

“But I am not special. I am just a girl.”

“You are the daughter of Obed Ramotswe,” said the driver. “He is a great man. That is why you are riding up here.”