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.
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.
Congo Bill is hired to locate an heiress lost somewhere in Africa.
A cult of Hindu tiger worshippers and a gang of Western outlaws try to cheat a young woman out of rich mines that belong to her.
The story follows General George Armstrong Custer's adventures from his West Point days to his death. He defies orders during the Civil War, trains the 7th Cavalry, appeases Chief Crazy Horse and later engages in bloody battle with the Sioux nation.
Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.
Calvin Drake employs a group of low-lifes to drive away land owners along the path of a new railroad; Red Ryder opposes this strategy.
The Hazards of Helen is an American melodramatic adventure film serial of 119 twelve-minute episodes released between November 7, 1914 and February 24, 1917. Most episodes of this serial are presumed lost.
Jesse James wants to start a new life in a new location, but quickly finds himself wrapped-up in protecting townsfolk from the machinations of evil oilmen.
Buffalo Bill Cody battles a gang of outlaws secretly headed by an unscrupulous lawyer.
Roberts and Moore played an army scout and a pony express rider who come to the aid of settlers terrorized by a greedy rancher-turned-outlaw.
When Pegleg and his Black Raiders threaten the westward expansion of the United States, the government sends Kit Carson and David Brent to straighten things out.
Beatrice Fairfax, the original advice-to-the-lovelorn reporter and her friend and not-so-secret admirer Jimmy Barton investigate calls for help and escape exotic perils and dangers. Episodes include exciting and fun stories of baby-napping, blackmail, jewel thievery, disguise, counterfeiting, and the long-unseen episode featuring entrancing cult starlet Olive Thomas and the real New York Yankees and Giants playing a game in the Polo Grounds.
Two investigators for a stagecoach company are assigned to find out why the company's stages keep being ambushed. They discover that the culprits are white men disguised as Indians, and they set out to discover who is behind the plot.
Irrepressible Helen Rhinelander, the daughter of a railroad president. A dastardly villain, Segrue, however, desires not only Helen but also the plans for a new railroad. Happily, Helen's childhood sweetheart, Paul Storm, now an engineer, is right there to protect the damsel-in-distress through the serial's 15 exciting chapters.
Richard Grant, imprisoned in India for a crime he did not commit, escapes and makes his way to Africa.