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 U.S. marshal is sent to investigate a gang that is stealing horses from the cavalry.

During a stick-up, a woman is excited by the criminal and joins him on his crime spree.

Flora Hawks is in love with the overseer of Tarzan's African estate. After a search for a legendary city of diamonds, Tarzon races with his pet lion Jad-bal-ja to save Haws from being sacrificed to a lion-god.

A dead criminal's daughter falls in love with a small-time crook and tries to get him to reform before he winds up like her father.

Two young men, one rich, one middle class, both in love with the same woman, become US Air Corps fighter pilots and, eventually, heroic flying aces during World War I. Devoted best friends, their mutual love of the girl eventually threatens their bond. Meanwhile, a hometown girl who's the lovestruck lifelong next door neighbor of one of them pines away.

A trucker with a pregnant wife fights a New York mobster's protection racket.

After her father is murdered, a girl joins the police force in an effort to track down the killers.

Two men running a carnival airplane ride are hired to fly to retrieve what they think are photos for a reporter. Actually, they are retrieving diamonds stolen from a noted gem dealer. As it turns out, their plane crashes on the very estate of the dealer. Thinking the duo are police officers, the dealer offers his home for their convalescence from the accident. Meanwhile, the diamonds have been snatched by a kleptomaniac dog and buried on the estate. When the smugglers track down the pair, they try to convince the dealer that they are officials from an institution from which the two have escaped. Before long, the carnival fellows, the crooks, the gem dealer and his family, along with a platoon of cops, are tearing up the grounds to find where the dog has buried the diamonds.

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.