A military intelligence officer and a pretty reporter try to find a scientist whose inventions can destroy the world.

Animal trainer Clyde Beatty heads a rescue party in search of his girl, Ruth, and her father who get lost looking for an uncharted island. His dirigible crashes into the jungles of the island. When he locates Ruth, he learns that her father has disappeared. The ensuing search is hindered by greedy gold hunters and wild animals.

When the ancient continent of Mu sank beneath the ocean, some of its inhabitant survived in caverns beneath the sea. Cowboy singer Gene Autry stumbles upon the civilization, now buried beneath his own Radio Ranch. The Muranians have developed technology and weaponry such as television and ray guns. Their rich supply of radium draws unscrupulous speculators from the surface. The peaceful civilization of the Muranians is corrupted by the greed from above, and it becomes Autry's task to prevent all-out war, ideally without disrupting his regular radio show.

From his secret laboratory, Captain Z-Ro and his associates use their time machine, the ZX-99, to learn from the past and plan for the future.

Flash Gordon, Dale Arden and Dr. Zarkov return to the planet Mongo for an antidote to the Purple Death, which wreaking destruction on Earth. However, Ming the Merciless has other plans for them.

A 15 episode serial in which Blake battles the "Scorpion" over possession of a 'death ray' machine.

Superhero Captain America battles the evil forces of the archvillain called The Scarab, who poisons his enemies and steals a secret device capable of destroying buildings by sound vibrations.