The female leader of an international crime ring steals a valuable artifact that can give her the power to control men's minds. Federal agents are dispatched to get it back and stop her evil plans.

Feature version of the 1949 serial, KING OF THE ROCKETMEN: Young member of scientific group uses new rocket-powered flying suit to thwart shadowy saboteur known only as "Dr. Vulcan".

Although ostensibly the grand-son of the legendary hero, Clayton Moore's Ken Mason is little more than a cowboy in a black mask in this 12 chapter Republic serial. Mason, the head of the telegraph line work crew, assumes his ancestor's trade-mark mask (but not whip) in order to prevent a local czar (Roy Barcroft) from sabotaging the burgeoning telegraph line. Pamela Blake, a brunette starlet formerly known as Adele Pearce, played Mason's imperiled girlfriend, and the serial also benefitted from the usual competent work of Republic's great stunt-performers, including Dale van Sickel, Tom Steele, Eddie Parker, and Joe Yrigoyen.

A Martian invader crashes his spaceship conveniently close to the workshop of a scientist who is developing an interplanetary craft. If the extraterrestrial Purple Monster can complete the rocket ship and return to Mars, he will be able to start a full-scale invasion of Earth. Good thing Craig Foster sets out to thwart the Monster's mission!

Prof. Millard pretends to be dead and helps Jeff King ferret out Vulcan, the evil traitor at the science academy. Donning his Rocket Man costume King goes from one hair raising rescue to the next in order to keep the newly invented Decimator out of the clutches of Vulcan and his minions.

A private eye and her sidekick solve the case of a dead client.

A private detective is offered a job protecting a rich business man from suspected blackmail. Before he can accept the case a murder is uncovered.