When the reporter Edward Malone is sent to interview the formidable Professor Challenger about his accounts of strange prehistoric beasts on a remote plateau in South America, he expects to be given short shrift by the researcher, notorious for man-handling nosy enquirers. But Challenger, impressed by the young journalist's thirst for adventure, invites Malone along on his next expedition, plunging him into a mysterious and dangerous world populated by dinosaurs and murderous ape men.