Edward Malone, a reporter for the Daily Gazette, asks his news editor, McArdle, for a dangerous and adventurous mission in order to impress the woman he loves, Gladys Hungerton. He is sent to interview the cantankerous Professor Challenger, who has become notorious for claims made about his recent expedition to South America. The professor has been plagued by intrusive reporters and, being a formidable man of great strength, has taken to forcibly ejecting them, despite the resulting police prosecutions. To gain entry Malone pretends to be an honest enquirer, but is quickly discovered, assaulted and thrown into the street. Although this is witnessed by a policeman, Malone does not press charges as the original deceit was his. Challenger is suitably impressed, and decides to reveal something of his discovery of living dinosaurs in South America. Malone is invited to a scientific gathering that evening at which he volunteers, along with the biologist Professor Summerlee and the Amazon adventurer Lord John Roxton, to travel to South America to investigate the claims. After a long and arduous journey they reach the plateau. But one of their local guides has a score to settle with Roxton and destroys their temporary bridge across a precipice, trapping the explorers on the dinosaurs' plateau, where he expects them to meet their deaths.