The People that Time Forgot (1918) was a popular "lost world" story, the second of Burroughs' trilogy, first published in Blue Book Magazine in 1918, after The Land That Time Forgot. Earlier "lost world" stories include Jules Verne's The Mysterious Island (1874) and Sir Arthur Conan Doyle's The Lost World (1912). [Pictured is the cover of the 1963 edition.]