The Trail of the Octopus

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.

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.

Molly Stewart, a teen at the top of her class who survives by working nights as a prostitute on Hollywood Blvd, finds her world beginning to fall apart when a depraved, necrophiliac serial killer begins targeting LA’s streetwalkers.

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.

A police detective is caught up in a plot to steal two million dollars in bonds.

Buffalo Bill Cody battles a gang of outlaws secretly headed by an unscrupulous lawyer.

A movie serial in 12 chapters: The famous comic strip character is on a mission to protect a secret tunnel passage between China and India.

Evil Hassan slips back into his native land of Ahad and plots to overthrow his twin bother, Kasim, who has just been crowned the Caliph. Hassan enlists the aid of the chief Chamberlain, Faud and they send several henchmen into the royal palace, who then knock Kasim unconscious. Faud and Hassan dispatch a couple of different hirelings to take Kasim into another part of the town and murder him.Kasin comes to and gets away, but has been wounded. Omar, a beggar, takes Kasim to his home and nurses him back to health. But, it takes a few weeks for Kasin to get healthy and, by that time, Hassan has a firm grip on the duties of a Caliph. In a storeroom, Kasim finds a coat of mail with a great hawk emblazoned across the chest and promptly decides this is the costume he will wear while fighting to get his old job back. Meanwhile, the Emir of Telif shows up with his daughter, Princess Azala, with the intent of marrying her off to the local Caliph.

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.

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.

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.

A new town doctor arrives at the same time as local Indians needprotection from troublemaking looters.

An Indian rug is the key to the location of a lost treasure. When the rug's owner is murdered, it becomes a case for Forest Ranger Steve King

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.

A bunch of waterfront youths pursue the Sea Raiders, a gang of saboteurs.

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.

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.