Charlotte Uhlenbroek explores the mysteries of the forest floor. The forest floor is perhaps the worst and most inhospitable place of all - dark, damp and full of potentially dangerous wildlife, nowhere more forbidding than the original heart of darkness, the Congo. Confronted with walls of impenetrable poisonous plants, toxic snakes, spiders, killer ants, diseases and large predatory cats, you can't even sit down without being bitten. Charlotte overcomes the hazards, and with state-of-the-art technology and inventive field craft, she reveals the hidden world of the forest floor. To survive here, almost everything has to struggle for light. And while chimps and gorillas live here, Charlotte highlights the difficulties and problems they face surviving in this formidable place. Through the dense vegetation, she also glimpses the largest of all jungle dwellers - the forest elephant.