The period is the 1820's and the first wagon train leaves Independence heading west to Santa Fe. In order to maintain his power, the ruthless Official at Santa Fe must not let them arrive and he sends out his men to stop them. The wagon train then has to endure repeated attacks but is aided by a mysterious rider that shoots singing arrows and rides a painted stallion.

When his father is killed in a train wreck, Larry Baker vows to unmask a mysterious criminal called "The Wrecker," who has targeted the L&M Railroad for deadly" accidents."

Beyond Hell's Gate Pass is territory controlled by a man who calls himself King Carter; he uses a variety of schemes to prevent the railroad from being built, for fear it will finish his control of (what he considers) his land.

An expedition sets off for the last land of Mu, where legend has it that a killer death ray is emitted from the eye of a golden idol.

Corporal Larry Grant and Sergeant "Mac" McGowan, of the United States Marine Corps, are rival for the love of Frances Schiller, but team up to hunt down "The Tiger Shark," a mad, scientific wizard who is holding Sergeant William Schiller, Frances' brother, a prisoner on a wild, jungle island in the Pacific.

Hammond, owner of the town's stagecoach line and a leading citizen, is opposed to Idaho becoming a state, and kills Randolph Meredith, owner of the town's newspaper, for endorsing it. Meredith's sister Barbara, expert with a bullwhip and pistol, dons a black costume and mask and becomes "The Black Whip", dealing a blow to Hammond and his gang each time they perform some heinous act in their efforts to keep the town, and their power over it, unchanged. Aided by government agent Vic Gordon, Barbara confronts Hammond in a final showdown just as the town votes on whether or not to accept statehood.

A group of flying cadets have to clear themselves of a murder charge, while trying to stop a traitorous scientist from selling secrets to the Nazis.

A group of street kids battle a terrorist gang led by a Japanese spy.

Hank Davis, foreman on a huge dam project, enlists the aid of his two flyer friends when a sinister figure known as The Black Ace leads his Mystery Squadron of masked pilots in an attempt to destroy the dam.