'The Challenger Encounters' is an omnibus edition of Arthur Conan Doyle's two best Professor Challenger novels. The first one, 'The Lost World', was a big influence on Michael Crichton's 'Jurassic Park'. Here the belligerent professor leads an expedition to a remote South American plateau in order to prove that dinosaurs and other prehistoric creatures have survived into the modern age. In the second adventure, 'The Poison Belt', Challenger discovers that the Earth is about to come into contact with a belt of poisonous ether, which looks set to bring about the end of humanity...