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.

An internationally-notorious criminal scientist returns to the US to sell his latest invention, a disintegrating gas, to a foreign power. When he arrives, however, he is spotted by a young Coast Guard man, whom he kills - and thus earns the enmity of the entire US Coast Guard, but especially the murdered Guardsman's older brother who, together with his reporter-girlfriend and her comical photogra...

A range lawman (Ken Maynard) unmasks a black-cloaked phantom killer (Sheldon Lewis).

There is trouble between the Dunbar brothers when Wally proposes to Bonnie on his brother's behalf only to have her accept him. Their feud is interrupted when they have to go after a con man who has cheated the bank out of $5000 by using a gold brick. With the outlaw captured, Wally now tries to get his brother and Bonnie together.

Dick Tracy's foe for this serial is the crime boss and Masked Mystery Villain The Spider/The Lame One and his Spider Ring. In the process of various crimes, including using his Flying wing and sound weapon to destroy the Bay Bridge in San Francisco and stealing an experimental "Speed Plane", the Spider captures Dick Tracy's brother, Gordon. The Spider's minion, Dr. Moloch, performs a brain operati...

An internationally-notorious criminal scientist returns to the US to sell his latest invention, a disintegrating gas, to a foreign power. When he arrives, however, he is spotted by a young Coast Guard man, whom he kills - and thus earns the enmity of the entire US Coast Guard, but especially the murdered Guardsman's older brother who, together with his reporter-girlfriend and her comical photogra...

Dick Tracy's foe for this serial is the crime boss and Masked Mystery Villain The Spider/The Lame One and his Spider Ring. In the process of various crimes, including using his Flying wing and sound weapon to destroy the Bay Bridge in San Francisco and stealing an experimental "Speed Plane", the Spider captures Dick Tracy's brother, Gordon. The Spider's minion, Dr. Moloch, performs a brain operati...

A cowboy called The Thunderbolt Kid comes to the aid of a town that is being threatened by outlaws who don't want a railroad to go through the town.

An eclectic group of people are stalked by a masked killer in an old mansion.

A range lawman (Ken Maynard) unmasks a black-cloaked phantom killer (Sheldon Lewis).