Oil barons from Mercury are looking for places to drill in Texas when an Earthling picks up their thought transmissions and thinks he's developed telepathy. He stows away on their craft to get in on their claim. He doesn't know that their craft has returned to Mercury, so when he disembarks, he tries to rabble rouse the locals against the aliens. When they don't respond, he realizes that he is not telepathic. All Mecurians project their thoughts, and he is on another planet.; An assistant to a professor arranges to dispose of the man's glasses so he must drive a dangerous road at night. When the man has an accident and dies, the assistant plots to sell his invisibility potion to a foreign power. He drives to his buddies to announce the professor's death, but they ignore him, and he thinks he must be invisible because he spilled a bit of formula on himself. He rushes back along the bad road to the lab and has a fatal accident. What he doesn't know is that his buddies really don't like him much and were ignoring him on purpose to teach him a lesson in manners and that the professor's formula didn't really work.; A scientist takes a handgun back to 1756 for protection when confronting a gunsmith he hopes to stop from developing his 'ultimate weapon' so that wars will not be as devastating. His fighting skills are quite poor, however, and the gunsmith and his apprentice easily overpower him. He panics, drops the gun, and hits the recall button for his time machine. He doesn't realize he has supplied history with the gunsmith's 'ultimate weapon'.; Freddy Kruger is dissatisfied with his life on a space colony, so he invents a story of plague wiping out everyone and requests permission to use the matter transporter to return to Earth. Permission is granted and he plants a bomb to destroy the device after he uses it so he will be an old man before any ship from Earth can reach the colony. Unfortunately, when he finds himself back on Earth, he finds he has been quarantined.; A Mercurian joins the staff of a newspaper to perpetuate a hoax of saucers landing from Mercury on purpose so that people will not believe a real invasion is underway until far too late. Fortunately for Earthlings, he is unable to convince his superior on Mercury that there are people on Earth.; Chinese communists disguise a submarine as a sea serpent to shoo away fisherman from waters which they wish to keep for themselves, but they attract the attention of a larger creature which pulls them down into the depths.