Author and amateur astronomer John Putnam and schoolteacher Ellen Fields witness an enormous meteorite come down near a small town in Arizona. Putnam becomes a local object of scorn when, after examining the object up close, he announces that it is a spacecraft, and that it is inhabited...
Martians come to Earth to build an H-bomb strong enough to blast Earth out of orbit so that Mars can be moved into its place in closer proximity to the sun. Super-scientist Larry Martin, inventor of the first stratospheric-flight spaceship as well as a jet-powered personal flying suit with helmet, is called upon by the government to investigate ramped-up UFO reports occasioned by the Martians' spaceships. The Martians, meanwhile, led by Marex, engage a renegade earth scientist and a gaggle of gangsters to help them steal supplies, operate a menacing robot, and build their bomb. This movie serial in 12 chapters was originally planned as a sequel to "Radar Men From The Moon" with Commando Cody as the hero but at the last moment the main characters' names were changed and all other references to that serial removed from the script.
Research chemist Barnaby Fulton works on a fountain of youth pill for a chemical company. One of the labs chimps gets loose in the laboratory and mixes chemicals, but then pours the mix into the water cooler. When trying one of his own samples, washed down with water from the cooler, Fulton begins to act just like a twenty-year-old and believes his potion is working. Soon his wife and boss are also behaving like children.
Reporters Clark Kent and Lois Lane arrive in the small town of Silsby to witness the drilling of the world's deepest oil well. The drill, however, has penetrated the underground home of a race of small, furry people who then come to the surface at night to look around. The fact that they glow in the dark scares the townfolk, who form a mob, led by the vicious Luke Benson, intent on killing the strange people. Only Superman has a chance to prevent this tragedy.
When a group of astronomers calculate a star is on a course to slam into Earth, a few days before, it's accompanying planet will first pass close enough to the Earth to cause havoc on land and sea. They set about building a rocket so a few selected individuals can escape to the planet.
The unassuming, nebbishy inventor Sidney Stratton creates a miraculous fabric that will never be dirty or worn out. Clearly he can make a fortune selling clothes made of the material, but may cause a crisis in the process. After all, once someone buys one of his suits they won't ever have to fix them or buy another one, and the clothing industry will collapse overnight. Nevertheless, Sidney is determined to put his invention on the market, forcing the clothing factory bigwigs to resort to more desperate measures...
The film's storyline involves five survivors, one woman and four men, of an atomic bomb disaster. The five come together at a remote, isolated hillside house, where they try to figure out how to survive.
Jewel thieves become interested in an invisibility formula invented by Professor Nakazato and want to use his invention to acquire a diamond necklace called the "Tears of Amour."
A scientist working on cures for rare afflictions, such as a bone softening agent made from molds to allow him to correct the spinal deformity of his nurse, finds the physical causes of lycanthropy in wolf-man Larry Talbot and of vampirism in Count Dracula, but himself becomes afflicted with homicidal madness while exchanging blood with Dracula.
A famous scientist invents a humanoid robot (the titular "monster"), so a greedy rival scientist plans to steal it for use in his criminal plans. His henchmen often kidnap a trained gorilla (the titular "ape") from the zoo, to aid in the schemes.
Grave robbers open the grave of the wolf man and awaken him. He doesn't like the idea of being immortal and killing people when the moon is full so tries to find Dr. Frankenstein, in the hopes that the doctor can cure him. Dr. Frankenstein has died; however, his monster is found.
Frankenstein's unscrupulous colleague, Dr. Bohmer, plans to transplant Ygor's brain so he can rule the world using the monster's body, but the plan goes sour when he turns malevolent and goes on a rampage.
Dr. Jekyll believes good and evil exist in everyone and creates a potion that allows his evil side, Mr. Hyde, to come to the fore. He faces horrible consequences when he lets his dark side run amok.
Dr. Paul Carruthers is frustrated because he thinks his employers, Mary Heath and Henry Morton, have cheated him out of the company's profits. He decides to get revenge by altering bats to grow twice their normal size and training them to attack when they smell a perfume of his own making. He mixes the perfume into a lotion, which he offers as a gift to Mary and Henry. When they turn up dead, a newspaper reporter decides to investigate.