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".

A warlord from Mars recruits an Earth industrialist with a Nazi past to manufacture weapons by means of which Mars can take over the Earth. Feature version of the 1951 movie serial "Flying Disc Man from Mars".

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!

Mota is a Martian representative, who has come to impose interplanetary law on the Earth (which has become too dangerous); opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.

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.