Demonstrating that a little knowledge is a dangerous thing, a convicted strangler studies the paranormal and finds a way to render himself invisible. Once he escapes, he sets out to find and eliminate five women who remind him of the mother he murdered. A police lieutenant sets out to safeguard them and bring the invisible killer to justice.

A space ship crash lands on the third planet of a distant solar system, killing all hands except for a young boy named Tang. The rescue ship arrives some 20 years later. One of the crew, a girl named Linda meets Tang and falls in love with him. They are attacked by the native humanoids of the planet and many of them are killed off. Also, the crew encounters many strange beasts on this strange, but somewhat familiar world.

An alien is dispatched from a faraway galaxy to take over the Earth by "duplicating" humans and creating a race of zombies.

An expedition to the lunar ice caves contracts a deadly moon-fungus. Stopping en route they contaminate a space station with the fungus, which soon begins to take over the entire place.