A gang of Tripolitan pirates swooped down and kidnapped 13 wealthy brides, whom they held for ransom.
A superhero known as The Black Commando battles Nazi agents who use explosive gases and artificial lightning to sabotage the war effort.
A young newspaperwoman travels to a South Seas island to search for buried treasure.
A criminal mastermind known as The Crimson Ghost is out to steal a device called the Cyclotrode, which can short-circuit all electrical current on the planet.
An accomplished aviator sets out to locate treasure hidden by one of his ancestors. He encounters interference from various adversaries.
Dusty Bates observes some smuggled jewels hidden in a crate aboard a ship; he is pursued by low-lifes when the crate is put ashore.
A young girl journeys to Africa to find her father, an explorer who vanished in the jungle.
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.
Prior to the United States' involvement in World War II, the masked vigilante Spy Smasher fights Nazi agents operating within the US, led by the treacherous sabotage leader codenamed The Mask.
The obsessive scientist Dr. Miller is working on a matter-transmitter invention called the Paratron; a conspiratorial team of spies and no-goods pursue him to Alaska, trying to steal the device.
A police detective is caught up in a plot to steal two million dollars in bonds.
Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.
Jerry Blake (aka Federal Operator 99) teams-up with Joyce Kingston to thwart the plans of escaped crime boss Jim Belmont.
An expedition arrives on an uncharted jungle island to rescue the local natives, led by a jungle boy, from a volcano that is about to erupt.
Escaped Prisoner 39013 impersonates the rich and influential Horace Granville, allowing him to create a variety of disasters. Fortunately, he is thwarted repeatedly by three daring circus daredevils.
Greedy traders have kidnapped a researcher, hoping he will reveal the location of a treasure in a hidden village. Family and friends of the researcher come looking for him. Adventure ensues.
A team of two-fisted insurance investigators (one of whom disguises himself as The Masked Marvel) endeavor to discover and thwart the loathsome saboteur Sakima.
Congo Bill is hired to locate an heiress lost somewhere in Africa.
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!
Claire Forrest seeks her kidnapped scientist father, hidden somewhere on Mystery Island. He is held and forced to work on diabolical inventions by Captain Mephisto, a costumed villain.