The California-Yucatan Railroad, being built for the good of Mexico, is under siege by a gang of terrorists hoping to force its sale; no one can prove their connection to profiteer Marsden. Manuel Vega, aged co-owner, calls in the aid of his nephew James, great-grandson of the original Zorro. Alas, James seems more adept at golf than derring-do; but after he arrives, Zorro rides again! Can one black-clad man on horseback defeat a gang supplied with airplanes and machine guns?

The masked hero leads a fighting force to fight a villian who plots the conquest of The Republic of Mexico.

Strategic targets on Earth are being destroyed by an unknown weapon. Government security head Henderson suspects it's an "atomic ray" originating from the moon! He assigns Commando Cody, scientist and man of action with a secret flying suit, to investigate. Soon, Cody is battling Earth thugs in the pay of Krog the moon man and making trips in his experimental rocket to the moon itself, in a perilous and all but singlehanded effort to thwart the planned invasion of Earth.

Tom Grant has found a rich gold vein and Bart Eaton is after it. Tom's sister Mary heads for the gold fields and Eaton and his men follow. Eaton teams up with Ace Daggett who plans to doublecross him and get the gold for himself. They frame Tom for murder and then try to get him to sign over his claim. The famous scout Tex Houston is on hand, escaping the attempts on his life, saving Mary from various perils, and trying to bring in the real killer and clear Tom.

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

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.

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.

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

Tarzan, who has returned to Africa after living in England, sets off to Guatemala in search of an old friend who may have survived a plane crash there. Also in Guatemala are Ula Vale and Major Martling who are out to find the riches of the Green Goddess. They join forces after they learn that a competitor, Raglan, has already set out ahead of them. Tarzan has to rescue everyone after they are taken prisoner. When they get to the hidden city, Tarzan finds his friend alive and the fabulous treasure.

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.