Two escaped convicts are found hiding in a rocketship built by a renegade inventor, who forces them to become the crew for a trip to the Moon. Also on board, as inadvertent stowaways, are his assistant and his secretary; and none of them are aware that the inventor is actually a Lunarian explorer sent to Earth by the dying Lunar civilization and the only remaining male member of that civilization.
Aliens from Outer Space are slowly switching places with real humans -- one of the first being a young man about to get married. Slowly, his new wife realizes something is wrong, and her suspicions are confirmed when her husband's odd behaviour begins to show up in other townspeople.
After exposure to radiation, an atomic research scientist finds himself changing into a murderous, lizard-like creature every time he is exposed to sunlight.
A man and wife are terrorized by Mad Scientist Dr. Callistratus who was executed but has returned to life with a heart transplant. Along with his crippled assistant Carl, the 'anemic' Mad Scientist, believed to be a vampire, conducts blood deficiency research on the inmates of a prison hospital for the criminally insane to sustain his return to life.
An astronaut returns to Earth as the no-pulse host of an alien monster's embryos; he is discovered by a loony farmer who find ways to feed his new critter.
With his assistant, Laura Hutchinson, Dr. David Conway develops a device to advance the fledgling science of earthquake prediction. After forecasting a large trembleor that will rock California within twenty-four hours, Conway cannot persuade the Governor to act. When the prediction proves true and further tests indicate that there are more quakes to come, Conway and Laura seek to perfect their device. Subsequent tests deep within Carlsbad Caverns discover an unknown element—E-112—that is responsible for the earthquakes and threatens to destroy the globe if it ever reaches the surface. The team determines that with only four weeks until Armageddon, the race is on to neutralize the killer element before it takes a devastating toll.
When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save one of the astronauts Colonel Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.
Baron Victor Frankenstein has discovered life's secret and unleashed a blood-curdling chain of events resulting from his creation: a cursed creature with a horrid face — and a tendency to kill.
A test rocket carrying wasps to outer space, to study the effects on them of weightlessness and radiations, crashes out of control back to Earth, into the jungles of Africa. The two astrobiologists in charge of the test mount an expedition to the Darkest Continent to retrieve their experiment, only to find the wasps have grown to giant size which are panicking all forms of life as they quest for food.
A wealthy business man discovers he has a brain tumor and seeks medical help. The business man finds a scientist experimenting with transplanting monkey heads on different monkey bodies. The business man decides to steal the head of Nostradamus from the prophet's crypt.
In California, an old man grieves the loss of his wife, and dies the day after she is buried. However, the space soldier Eros and his mate Tanna use an electric device to resurrect them both, alongside the strong Inspector Clay, who was murdered by the alien-controlled dead couple. When the populations of Hollywood and Washington DC see flying saucers on the sky, a colonel, a police lieutenant, a commercial pilot, his wife and a policeman try to stop the aliens.
An American reporter smells a story when he is stranded in an Iron Curtain country where the local dictator is using gamma rays to transform children into mutated henchmen.
In 19th century England, a noted brain surgeon rescues a former student from being hanged on a false conviction for murder, and spirits him away to an ancient, repurposed abbey far in the countryside. There, he connives his pupil into assisting him in mapping the functions of the various parts of the human brain, using living subjects who are under a terrible animation-suspending drug called "black sleep". Subsequently, the student, along with the daughter of one of the subjects, discover that most of these subjects have survived but are being kept in a dungeon-like cellar, in various stages of physical and mental derangement...
A scientific experiment involving subjecting a corpse to an extreme charge of electricity accidentally revives an executed criminal and makes him impervious to harm, allowing him to seek revenge on his former partners, and deal similarly with anyone else who gets in his way.
A marine biologist and a government agent investigate mysterious deaths and rumors of a sea monster in a secluded ocean cove, and find themselves involved with a marine biology professor conducting secretive experiments, international spies trying to steal his secrets, a radioactive light on the sea bottom, and the malevolent thing which guards it.
Dr. Eric Vornoff, with the help of his mute assistant Lobo, captures twelve men for a grisly experiment; His goal to turn them into supermen using atomic energy. Reporter Janet Lawton, fiancée of the local lieutenant, vows to investigate Vornoff's supposedly haunted house.