The Great Alaskan Mystery

The Wrecker wrecks trains on the L & R Railroad. One of his victims is Larry Baker's father. Baker wants to find the evildoer, among a host of suspects, but it will be difficult since the Wrecker can disguise himself to look like almost anyone

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.

A newspaper publisher and his Korean servant fight crime as vigilantes who pose as a notorious masked gangster and his aide.

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.

The mysterious Don Del Oro ("Lord of Gold"), an idol of the Yaqui Indians, plans to take over the gold and become Emperor. Francisco was put in charge of a legion to combat the Yaqui tribe and protect the land, but when attacked Zorro came to his rescue. Francisco's partner recognized Zorro as the hidalgo Don Diego Vega, then ask him to take over the fighting legion as his alter-ego Zorro.

A mad scientist named Dr. Satan plots to steal key pieces of technology to enable him to build an army of robots based on his prototype to conquer America. The only one standing in his way is Bob Wayne, who fights Satan as the enigmatic Copperhead. Mysterious Doctor Satan is a 1940 film serial named after its chief villain. Doctor Satan's main opponent is the masked mystery man, "The Copperhead", whose secret identity is Bob Wayne, a man searching for justice and revenge on Satan for the death of his step-father. The serial charts the conflict between the two as Bob Wayne pursues Doctor Satan, while the latter completes his plans for world domination.

Richard Grant, imprisoned in India for a crime he did not commit, escapes and makes his way to Africa.

Mandrake and his team attempt to prevent "The Wasp" from stealing and using a new Radium invention.

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.

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.

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.

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.

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.

Commando Cody, 'Sky Marshal of the Universe', works with American scientists Joan Gilbert and Ted Richards in the development of a flying suit and a rocket to the Moon. When the nation's defences are being sabotaged and destroyed, Cody learns that an atomic-gun is being used and that the men on the moon are the culprits.

The Daily Clarion hires detective story writer Steve Colt to investigate the deaths of a group of scientists working on an atomic rocket development project. Behind the killings is fortune teller Sombra, a spy from an Asian country intent on world domination, who is determined to pilfer the atomic rocket by luring workers from the project to her parlor and killing them with black widow spider venom when they refuse to cooperate.

A serial in 12 chapters. Tarzan goes to Guatemala to find his lost friend, D'Arnot. On the way he helps Major Matling search Mayan ruins for hidden jewels and an idol containing the formula for a powerful explosive. D'Arnot and the idol are rescued, but the idol falls into the clutches of the explorer Raglan.

A Nazi spy ring is after a chemical formula that increases the power of ordinary gasoline for U.S. Army aviation use. Two U.S. chemical companies are developing the formula, with each working on half for security purposes. The spies get half the formula and know that either of two chemists, Robert Norton or Tom Fielding, knows the rest. They capture Fielding, through a ruse by gang member Linda Pavlo, and threaten the life of his sister Nancy and his mother if he does not give them the formula. To protect his friend Fielding, who does know the formula and is engaged to Nancy, Tom pretends to know the secret and boards the Dawn Express plane with the spy leader and his gang.

A Nazi spy passes himself off as an optometrist in San Francisco's waterfront district. Someone robs him of his code book, and he must get it back.

Broadway gamblers stumble across a plan by Nazi saboteurs to blow up an American battleship.