Before written language there were still poems and stories, and tonight's Bookmark offers a glimpse of one pre-literary culture where tales of gods, heroes and magical animals have a significance that they have not had in western Europe since Homer. The Waura tribe of the Matto Grosso in central Brazil was first contacted by the white man as late as the 1950s: they still tell their stories of the muddy water beings who are both their ancestors and makers. In tonight's film the tribal storyteller, Aruta, recounts one of their key myths, a story as powerful, fresh and keenly imagined as the opening chapters of Genesis.