A gaseous alien arrives on Earth to warn people to evacuate before its race invades. It attempts to communicate with humans telepathically, but they disregard his warning as madness or a trick. Convinced that the humans' lack of fear is due to some impenetrable defence, the alien leaves and warns its people to call off the invasion.; A man descends in a bathysphere into a pit so deep that he is surprised to find a waterless cavern beneath it occupied by elves banished long ago by a wizard. They stole the magic ball that kept Atlantis safe from the waves and so a sorcerer cast a spell that would send them to the deepest pit in the Earth. They offer to make the man ruler of humans if he returns them to the surface would. He agrees, but then has second thoughts about unleashing their mischief upon unsuspecting humanity and destroys the bathysphere, accepting underground exile in the process.; A man spends twenty years building a time machine in order to use knowledge of the future to enrich himself. He travels to 2010 and memorizes stock market and horse race information from the newspaper archives. When he tries to return to the past, however, he finds that he accidentally left his time machine in a futuristic garbage processor, and it has been disintegrated.; A rocketship test pilot in the year 2089 takes an experimental rocket on a test flight. He faces an oxygen leak caused by a collision, alien raiders and other hazards before returning safely to Earth.; A short child mocked for his height takes comfort from his one friend and his love of airplanes. He is rejected by the air force because of his height, but when his friend designs an experimental rocket that can only be piloted by a short man he becomes the first man on Mars.