A young boy lets the animals out of their cages at the Zoo, to set them free, but the animals start taking over the town.

Teenage friends Kit and Libby make prank phone calls for fun but then find themselves involved in a brutal double murder committed by one of their targets.

To keep peace, an Army captain (Willard Parker) hunts for an outlaw-gang leader (Kent Taylor) who is raiding Indians.

An evil alien brain, bent on world domination, takes over the body of an atomic scientist, while a “good” alien brain inhabits the body of the scientist’s dog and waits…