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 man returning home after having fought in the Civil War discovers that corrupt politicians have taken over the county and are terrorizing and shaking down the citizens. He dons the costume of his ancestor, the famous Zorro, and sets out to bring them to justice.

Man-woman team of investigators uncover a gang whose mad scientist leader has developed an invisibility chemical and plans to build a mercenary army of invisible men.

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.

Jungle Jim is out to save Joan from an evil witch doctor whilst simultaneously fighting evil treasure hunter Barton.