Edward Malone is a man in love; the woman of his dreams being Gladys Hungerton. Gladys, though, is critical of Malone, as he has never done anything spectacular or dangerous to prove his love for her. Malone, being a journalist on the Daily Gazette, quickly finds a way in which he can impress Gladys. Malone therefore signs up to cover the expedition of Professor George Edward Challenger. Professor Challenger's scientific reputation has been damaged by his insistence that creatures thought to be extinct exist within the Amazon basin; and has therefore announced an expedition to regain his credibility. The expedition goes forth and is made up of Professor Challenger, Professor Summerlee, the Amazon adventurer Lord John Roxton, and Malone. The expedition also has a number of natives acting as guides and equipment carriers.