An egocentric professor leads an expedition on a journey into the Amazon on a mission to prove his theory that dinosaurs still survive there. On arrival, they find the prehistoric beasts are all too real - and only one of the dangers they face. Fantasy adventure, based on Arthur Conan Doyle's classic novel, starring Claude Rains, Michael Rennie and Jill St John.

Professor Challenger leads an expedition of scientists and adventurers to a remote plateau deep in the Amazonian jungle to verify his claim that dinosaurs still live there.