The idea had come from Burkhardt, the German. He thought that agriculture in dry lands like Botswana and Namibia could be transformed by growing crops under shade-netting and irrigating them with droplets of water on strings. You will have seen how it works, Mma Ramotswe: the string comes down from a thin hosepipe and a droplet of water runs down the string and into the soil at the base of the plant. It really does work. I've seen it done.

Burkhardt wanted to set up a cooperative out there, based on that old farmhouse. He had managed to raise some money from somewhere or other and they had cleared a bit of bush and sunk a borehole. They had managed to persuade quite a number of local people to join the cooperative, and they were already producing a good crop of squash and cucumbers when I first went out there with Michael. They sold these to the hotels in Gaborone and to the hospital kitchens too.

Michael began to spend more and more time with these people, and then eventually he told us that he wanted to go out there and live with them. I was a bit concerned at first-what mother wouldn't be-but we came round to the idea when we realised how much it meant to him to be doing something for Africa. So I drove him out there one Sunday afternoon and left him there. He said that he would come into town the following week and call in and see us, which he did. He seemed blissfully happy, excited even, at the prospect of living with his new friends.

We saw a lot of him. The farm was only an hour out of town and they came in virtually every day to bring produce or get supplies. One of the Botswana members had been trained as a nurse, and he had set up a clinic of sorts which dealt with minor ailments. They wormed children and put cream on fungal infections and things like that. The Government gave them a small supply of drugs, and Burkhardt got the rest from various companies that were happy to dispose of time-expired drugs which would still work perfectly well. Dr Merriweather was at the Livingstone Hospital then, and he used to call in from time to time to see that everything was in order. He told me once that the nurse was every bit as good as most doctors would be.