The Poison Belt (Professor Challenger)

Professor Challenger calls his team from The Lost World together again--Lord John Roxton, Edward Malone, and Professor Summerlee. He tells them to come to his home outside London, and to bring tanks of oxygen. When they arrive, they are taken to a sealed room because Challenger is convinced a belt of poisonous ether is going to flow over the Earth, and it could mean the end of humanity.