The summer rains of 1997 came hard to the old Transkei, and the Mzintlava, which runs down past Mount Ayliff towards the Umzimvubu, came up brown and fast. Between January and April, nine people from the villages along its banks went into the water and did not come out alive. When the river gave the bodies back, the people who pulled them onto the bank saw that the faces and the tops of the heads had been eaten away.

That is when the villagers began to say the word Mamlambo.

In Zulu and Xhosa tradition the Mamlambo is a river being, snake-shaped, feminine, associated with deep pools and with the kind of wealth that comes too fast and costs too much. She is dangerous and seductive, a cousin of the Mami Wata of West Africa. She is not, in the old stories, especially interested in eating faces. But by March 1997 the people of the Mzintlava had a description of what was in their river, and they gave it to the newspapers. It was about twenty metres long, they said. It had the head of a horse on the neck of a snake, the lower body of a fish, and short legs. At night it glowed green. It took people under, held them, and fed on the soft parts. Somebody, possibly a sub-editor, called it the Brain Sucker, and the name stuck.

The Star and the Cape Argus ran it. It went abroad. For a few weeks in the autumn of 1997 a river in the Eastern Cape had a monster with its own nickname, and journalists came to stand on the bank and look at it.

The police had a different story, and it was not a comforting one either. The victims, they said, had drowned in flood water, as people do every year in that part of the country when they try to cross swollen rivers, and their bodies had lain in the water for days before they were found. The Mzintlava is full of freshwater crabs. Crabs go for the soft tissue first: the eyes, the lips, the scalp, the throat. That is what the families had seen. The provincial government, under some pressure to do something about a twenty-metre horse-headed snake, sent people to look, and they found flood, and crabs.

The villagers did not accept this, and it is worth being fair about why. Nine deaths in one stretch of river in four months is a great many, even in a flood season, and the injuries were consistent and horrible. A monster with a name is, in some ways, easier to live beside than a river that simply takes people. And there is an older logic underneath: a Mamlambo does not appear in a river by accident. Somebody, the story goes, has been dealing with her, and the deaths are a price being paid.

The rains stopped. The river went down. The bodies stopped coming. No hunter, policeman or journalist ever saw the creature, and no photograph of it exists.

The Mzintlava still floods every few summers. People still cross it when they should not. The crabs are still there. So, on the maps of a certain kind, is the Mamlambo.