A fugitive, dangerous madman reaches an English village where he confronts his former partner who left him for dead in the jungle after their discovery of a diamond mine. When the former partner also claims to have since lost the mine and all its wealth, which he took all for himself, and though the partner is still living in a state of luxury , the madman takes up an offer from a crazed scientist to make him invisible, something the scientist has already done with experimental animals, so that he can take revenge.

Bomba the jungle boy swings into action when an elephant herd is threatened by ivory hunters.

Edited version of the 1939 Universal serial "Buck Rogers." A 20th Century pilot named Buck Rogers and his young friend Buddy Wade awake from 500 years in suspended animation to find that the world has been taken over by the outlaw army of Killer Kane.

A mysterious plague, the Purple Death, ravages the earth. Dr. Zarkov, investigating in his spaceship, finds a ship from planet Mongo seeding the atmosphere with dust. Sure enough, Ming the Merciless is up to his old tricks. So it's back to Mongo for Flash, Dale, and Zarkov.

Kurt Ingston, a rich recluse, invites the doctors who left him a hopeless cripple to his desolate mansion in the swamps as one by one they meet horrible deaths.