Dr. Ernst Grood , having already dominated the planet Ergro, now intends to take over the control of the Earth. Unfortunately for him, reporters oppose his sinister designs.
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.
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.
An escaped criminal impersonates a Police Commissioner, causing no end of trouble to a determined Federal Agent.
Dick Tracy battles spies and saboteurs in his efforts to bring to justice the Stark gang, a criminal family led by the vicious Pa Stark.
Two marine lieutenants battle a masked would-be world conqueror who uses electricity as a weapon.
Wealthy Irving Randolph is falsely denounced as a deliberate murderer by his greedy younger brother when Randolph, during a rifle shooting contest, accidentally kills a man with whom he has had an altercation. Fleeing to Australia, Randolph becomes known as the bandit Stingaree and is aided in his Robin Hood like adventures by his friend Howie and his sweetheart Ethel.
An accomplished aviator sets out to locate treasure hidden by one of his ancestors. He encounters interference from various adversaries.