The man absorbed this. “She can come back here. She has good fields. She could stay. She has many relatives out here, and they will look after her.” He turned to look at the van. “But you cannot get to her place in that van, Mma. You will have to leave it here and walk. It is not far to her place now—just half an hour or so along that way.”

“But we can’t leave the van stuck in the sand,” objected Mma Makutsi. “How will we get back to Gaborone? We cannot walk.”

“We won’t leave it in the sand,” said the man. “I will help you pull it out, and then we will leave it here. You can collect it when you have finished visiting Mma Potokwane. It will be perfectly safe.”

Mma Ramotswe and Mma Makutsi looked at the donkeys. One of them, clearly older than the other, grey about the muzzle and the eyes, appeared to be asleep on his feet, his head drooping, indifferent to the flies that buzzed about what looked like an open sore on one of his ears.

“They are very strong,” said the man, intercepting the glance. “They have pulled bigger vans out of there. You needn’t worry, Mma.”

“I have some rope,” said Mma Ramotswe. “Under the seat there is some rope that my husband put in there. We could use that, Rra.”

The man shook his head. “I have my own, Mma. I always carry it because I know that I need it. We can use mine.”

He walked round to the back of the cart and extracted a length of rope from a box nailed to the boards. Then he detached the yoke from the front of the cart and began to cajole the two donkeys into position in front of the tilting nose of the tiny white van. Mma Ramotswe was impressed by his businesslike manner—this was a man, she decided, who knew what he was doing. “You get in and steer, Mma,” he said to her. “Otherwise the wheels will point in the wrong direction and you’ll go further into the sand. Steer back into the middle of the road.”

Mma Ramotswe returned to the van and eased herself into the driver’s seat. The man now addressed Mma Makutsi, suggesting that she push at the back of the van while he pulled on the yoke at the front and persuaded the donkeys to take the strain. Then they both got into position, and the man started to shout at the donkeys.

Inside the cab, Mma Ramotswe felt the van move—but only slightly. Then, as the man gave a resounding smack to one of the donkeys, it moved again, rolling forwards as the wheels were dragged through the sand; only to stop and then roll back the few precious inches it had just achieved.

“Stop,” called out the man, both to the donkeys and to Mma Makutsi.