The Tributary is an anthropology adventure set in the Amazon basin that looks to identify and pinpoint more accurately when mankind first arrived in South America. A scientific expedition hopes to achieve this through the discovery of a suspected, genetically-isolated tribe deep in the forest, from which DNA samples will enable them to illuminate a period of man's evolutionary history of which very little is known. It soon becomes clear, however, as they travel further into the depths of the jungle, that an even greater discovery beckons, a discovery that will have profound implications for...