She gestured for them to enter and they walked across to meet her.

"I cannot see very well these days," explained Mma Potsane. "My eyes are getting worse and worse. That is why I didn't know who you were."

They shook hands, exchanging formal greetings. Then Mma Potsane gestured across to a bench which stood in the shade of the large tree beside her house. They could sit there, she explained, because the house was too dark inside.

Mma Tsbago explained why they were there and Mma Pot-sane listened intently. Her eyes appeared to be irritating her, and from time to time she wiped at them with the sleeve of her blouse. As Mma Tsbago spoke, she nodded encouragement.

"Yes," she said. "We lived out there. My husband worked there. We both worked there. We hoped that we would be able to make some money with our crops and for a while it worked. Then..." She broke off, shrugging despondently.

"Things went wrong?" asked Mma Ramotswe. "Drought?"

Mma Potsane sighed. "There was a drought, yes. But there's always a drought, isn't there? No, it was just that people lost faith in the idea. There were good people living there, but they went away."

"The white man from Namibia? The German one?" asked Mma Ramotswe.

"Yes, that one. He was a good man, but he went away. Then there were other people, Batswana, who decided that they had had enough. They went too."

"And an American?" pressed Mma Ramotswe. "There was an American boy?"

Mma Potsane rubbed at her eyes. "That boy vanished. He disappeared one night. They had the police out here and they searched and searched. His mother came too, many times. She brought a Mosarwa tracker with her, a tiny little man, like a dog with his nose to the ground. He had a very fat bottom, like all those Basarwa have."

"He found nothing?" Mma Ramotswe knew the answer to this, but she wanted to keep the other woman talking. She had so far only heard the story from Mrs Curtin's viewpoint; it was quite possible that there were things which other people had seen which she did not know about.