Mma Ramotswe arrived half an hour early, and after she had found a shady spot for the van, she decided to walk down to the edge of the water, some fifty yards away. It was very peaceful. Above her was an empty sky; endowed with so much room, so much light; on the other side of the dam, set back a bit, was Kgale Hill, rock upon rock. You could see the town on the other side of the wall, and you knew it was there, but if you turned your head the other way there was just Africa, or that bit of it, of acacia trees like small umbrellas, and dry grass, and red-brown earth, and termite mounds like miniature Babel towers. Paths led criss-cross to nowhere very much; paths created by the movement of game to the water, and she followed one of these down towards the edge of the dam. The water was light green, mirror flat, becoming blue in its further reaches. Reeds grew at its edge, not in clumps, but sparsely, individual needles projecting from the surface of the water.

Mma Ramotswe was cautious. There were crocodiles in the Notwane—everybody knew that—and they would be in the dam too, although some people denied it. But of course they would be here, because crocodiles could travel long distances over land, with that ungainly walk of theirs, seeking out fresh bodies of water. If they were in the Notwane, then they would be here too, waiting beneath the water, just at the edge, where an incautious warthog or duiker might venture. And then the crocodile would lunge out and seize its prey and drag it back into deeper water. And after that followed the roll, the twisting and churning, when the crocodile turned its prey round and round under water. That was how the end came, they said, if one was unfortunate enough to be taken by a crocodile.

There had been a bad crocodile attack at the end of the last rainy season, on the Limpopo, and Mma Ramotswe had discussed it with Mr. J.L.B. Matekoni. He had known the victim, who was a friend of a cousin of his, a man who had a small farm up on the banks of the river and who had crossed the water in his boat to drive some cattle back. The cattle had somehow managed to cross the river to the wrong bank, onto somebody else’s land, in spite of the fact that the water was high.