While in the Amazon rainforest, Professor Challenger shoots an animal he believes to be a pterosaur. Returning to England, Challenger crashes a lecture at the Natural History Museum, London held by his colleague, Professor Leo Summerlee. Challenger proposes an expedition to discover the home of the pterosaur, but is dismissed by the science community. However, hunter Lord John Roxton, and ''Daily Gazette'' columnist Edward Malone both volunteer to join and finance the expedition. A sceptical Summerlee also joins.
