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.
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.
An accomplished aviator sets out to locate treasure hidden by one of his ancestors. He encounters interference from various adversaries.
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!
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.
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.
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.
Disaster seems imminent when scientists discover that the planet Mongo is about to crash into Earth. Luckily, heroic young Flash Gordon is on hand to lead an investigative mission into outer space and onto the speedily approaching planet. There, he and his best girl, Dale, who is along for the ride, learn that Ming, the devious ruler of Mongo, has purposely put the planet on a collision course with Earth, and only Flash can stop him.
The nefarious Dr. Fu Manchu searches for the keys to the tomb of Genghis Khan, in order to fulfill a prophecy that will enable him to conquer the world. His nemesi, Dr. Nayland Smith and his associates fight to keep the evil doctor from getting his hands on the keys. In 1943 the serial was edited together into a feature movie also called Drums of Fu Manchu.
Daniel Robin has become mixed up with a band of criminals known as "the 13," and is shot when he refuses to do their bidding. His daughter Ruth, brought home from boarding school, reaches his bedside before he expires. He tells her that she will be given thirteen keys. Instructions will be provided with each key and, if she follows the instructions, she will eventually fully learn of her birthright. Many adventures then follow as Ruth attempts to solve the puzzle of each key and establish her true birthright.
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 police detective is caught up in a plot to steal two million dollars in bonds.
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 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.
Dr. Mabuse and his organization of criminals are in the process of completing their latest scheme, a theft of information that will allow Mabuse to make huge profits on the stock exchange. Afterwards, Mabuse disguises himself and attends the Folies Bergères show, where Cara Carozza, the main attraction of the show, passes him information on Mabuse's next intended victim, the young millionaire Edgar Hull. Mabuse then uses psychic manipulation to lure Hull into a card game where he loses heavily. When Police Commissioner von Wenk begins an investigation of this mysterious crime spree, he has little to go on, and he needs to find someone who can help him.
Government agents work to interfere with schemes to trick the Comanches into war with the Texans.
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.