At Port-la-Nouvelle, on the parched terrain of central Africa, Dr. Mallory watches as his clinic fails and dreams of discovering a third Nile that will make the Sahara bloom. When there is a trickle on the Local airstrip, and soon a river, the obsessed MaLLory claims it as his own creation. Joined by Noon, a silent adolescent girl who as a child ran with the local guerrillas; Professor Sanger, a documentary filmmaker with a fading reputation; and Nora Warrender, the widow of a Rhodesian veterinary surgeon, the remains of whose menagerie flourish exotically amid the land's new fertility, Mallory sets out for the river's source.