It is 1865 and Union prisoners use a military balloon to escape a Southern prison camp near the end of the Civil War. The balloon drifts for days and finally lands on a mysterious volcanic island with very unusual inhabitants. Also landing, in a better aircraft, is Rulu, a visitor from Mercury. She seeks a radio-active material that will enable her to manufacture an explosive that will destroy the world or, at least, the portion known as Earth in this 15 Chapter Serial from the 1950s.
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.
The CIA sends playboy Mike Trent to Alaska with agent Vee Langley, posing as his "nurse," to investigate flying saucer sightings. At first, installed in a hunting lodge, the two play in the wilderness. But then they sight a saucer. Investigating, our heroes clash with an inept gang of Soviet spies, also after the saucer secret.
Prof. Millard pretends to be dead and helps Jeff King ferret out Vulcan, the evil traitor at the science academy. Donning his Rocket Man costume King goes from one hair raising rescue to the next in order to keep the newly invented Decimator out of the clutches of Vulcan and his minions.
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.
Claire Forrest seeks her kidnapped scientist father, hidden somewhere on Mystery Island. He is held and forced to work on diabolical inventions by Captain Mephisto, a costumed villain.
Japanese master spy Daka operates a covert espionage-sabotage organization located in Gotham City's now-deserted Little Tokyo, which turns American scientists into pliable zombies. The great crime-fighters Batman and Robin, with the help of their allies, are in pursuit.
After The Daily Planet receives a letter from a mad scientist threatening to wreak destruction with his Electrothanasia Ray, Lois Lane heads out in the hopes of getting more information for a news story.
On a scientific expedition to Siam young Billy Batson is given the ability to change himself into the super-powered Captain Marvel by the wizard Shazam, who tells him his powers will last only as long as the Golden Scorpion idol is threatened. Finding the idol, the scientists realize it could be the most powerful weapon in the world and remove the lenses that energize it, distributing them among themselves so that no one would be able to use the idol by himself. Back in the US, Billy Batson, as Captain Marvel, wages a battle against an evil, hooded figure, the Scorpion, who hopes to accumulate all five lenses, thereby gaining control of the super-powerful weapon
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.
Dr. Bernard Adrian is a kindly scientist who seeks to cure a young woman's polio. He needs human spinal fluid to complete the formula for his experimental serum. Meanwhile, a vicious circus ape has broken out of its cage, and is terrorizing the townspeople. Can there be a connection?