Sir Arthur Conan Doyle's The Poison Belt follows on from The Lost World, but this time Professor Challenger trades the jungle setting for a room in his own house. Edward Malone, Lord John Roxton, and Professor Summerlee arrive at the Professor's home, each with a tank of oxygen - the result of receiving a puzzling behest from Challenger via telegraph. Challenger and his wife usher them into a sealed room - in his research the Professor has predicted that a poisonous ether belt is about to reach the earth and quite likely cause the end of the humanity.