A police detective is caught up in a plot to steal two million dollars in bonds.
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.
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.
Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.
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.
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.
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.
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.
Mota is a Martian representative, who has come to impose interplanetary law on the Earth (which has become too dangerous); opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.
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.
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.
Two British officers are assigned to collect information to convict Captain Kidd of piracy.
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.
The villain of this serial, the "Wolf Devil", who's head covering amazingly looks to be a REAL wolf's head, is determined to eradicate the non native races from Alaska.
The story of a boy, a dog, and a man. The boy discovers he is heir to a shipping line, and travels to Los Angeles, accompanied by inventor/radio operator Bob Whitlock and Irene Blaine. Their journey is aided by Pal, a wolf dog.
A Secret Service agent seeks his missing brother in Africa, and finds his mission complicated by ivory thieves, a girl with a mysterious past, and a troublesome gorilla.