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.

The struggle over the Bellamy estate ends with Michael Bellamy accused of murder and killed on the way to prison, while his brother, Abel Bellamy, takes control of the estate for his own nefarious plans.

A master criminal called The Spider puts the famous detective's brother under a hypnotic spell and turns him against Dick.

A 14-episode serial in which Mala, a Polynesian in the employ of U.S. Intelligence investigates sabotage on Clipper Island. A gang of spies causes the eruption of a volcano, for which our hero is blamed. He convinces the local Princess Melani of his innocence and helps her ward off a takeover by rival high priest Porotu.

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

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."

A murderous gang of counterfeiters has kidnapped the government's best engraver and is forcing him to print virtually undetectable phony money. The Secret Service sends its toughest agent, Jack Holt, and a female partner after the gang.

Tom Wayne rescues Clancy, Renard and Schmidt in the Arabian desert and they join him in going after El Shaitan, a bad guy who is never seen as he tries to wipe out the Foreign Legion.

A gang of street kids work with the FBI in their attempt to find and rescue their leader's father, a scientist who has been kidnapped by a terrorist group.

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.