After a military helicopter crashes in a remote valley in Africa, a lone survivor awakens without memory of his identity or mission. From the wreckage, he learns only his name: Roger Drum. Armed with instinctive survival skills, the amnesiac roams his new surroundings, discovering a bizarre lost world of dinosaurs, mammoths, sabretooth tigers, and primitive human tribes. Against the backdrop of this hostile new reality, Drum must come to terms with...