This is the second chapter in the world-famous Professor Challenger series written by none other than Sir Doyle. It was first released in 1913, about a year before WW1 devastated planet Earth. We find Challenger sitting in in a lonely room and sending messages to his friends from the Lost World. He asks them to come visit him outside of UK's capital and tells them all to grab as much oxygen as they can.
When they arrive, the professor takes them into a sealed room and tells about his discovery: the man has predicted that the planet is moving right into a belt full of poisonous substances that will put an end to mankind. That is why the professor sealed the room and told his followers to bring oxygen along. He believed that it would "beat" the ether that's about to hit Earth, and he turned out to be right.
When the tragedy happens, Challenger, his wife, and the three companions watch folks on the outside die. And when the last oxygen pack is emptied, they decide it's time to open the windows and look death in the eyes. However, they don't pass away. The professor concludes that the planet is not in the danger zone anymore and that they're all safe now. Next, they get into his car and embark on a journey towards London.
After they successfully arrive at his house, they learn that the ether doesn't kill - it only makes folks pass out. Soon, the whole world comes back to its senses and people go on with their lives like nothing happened. At the same time, the natural disasters did a lot of damage and killed numerous innocent citizens. The Poison Belt is a pretty awesome science fiction novel that introduced a lot of fresh ideas to the genre and is still considered to be a masterpiece.