The Lost World is an adventure story centered on the discovery of a prehistoric land deep within the Amazon, populated by various species of dinosaurs as well as ancient humanoids. The Poison Belt, while containing all of the principle characters featured in The Lost World, bears striking dissimilarities from its predecessor. Most notably, while The Lost World depicts a dangerous expedition into unknown jungle lands, The Poison Belt, while still featuring dangers, largely takes place in Professor Challenger's home during what the characters believe to be a world-ending event. Each story raises questions about the role of science in an increasingly modern world, presented with the slyly humorous approach Conan Doyle revealed in so many of his great works.