The Strings of Steel

An accomplished aviator sets out to locate treasure hidden by one of his ancestors. He encounters interference from various adversaries.

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.

Poor stenographer Gloria Graham believes that clothes make a woman successful in business and as a result she incurs great debts.

When wealthy Wall Street stockbroker Stephen Duane neglects his wife Julia for business, she consorts with philanderer Bert Brockwell. Finding them in an embrace forced by Brockwell, Stephen denounces Julia and leaves. After losing his fortune in the market, Stephen refuses Julia's offer to sell her jewels, and stays away for one year

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.

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.

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.

A famous scientist invents a humanoid robot (the titular "monster"), so a greedy rival scientist plans to steal it for use in his criminal plans. His henchmen often kidnap a trained gorilla (the titular "ape") from the zoo, to aid in the schemes.

Orphan Patience Sparhawk grows up poor until she becomes the ward of the wealthy Miss Tremont. Eventually out of gratitude Patience marries Miss Tremont's nephew, Beverly Peale, out of gratitude only to discover he is a drug user, making their marriage unhappy. When Beverly is found dead from a drug overdose Patience is accused of murder, put on trial and sentenced to die in the electric chair but is saved at the eleventh hour.