The story concentrated on a group of test pilots, busily experimenting with a revolutionary all-plastic airplane. Ace flyboy Brad Farrell (Richard Arlen) is determined to prove the practicality of the new aircraft, designed by Professor Blake (Thomas Ross), father of Brad's sweetheart Carol (Jean Parker). Back on solid ground, Brad must vie for Carol's attentions with his own brother, engineer Doug Farrell (Don Castle).
The mayor has sent for a gunslinger who, though appearing to clean up the town, is really to be the mayor's means of taking the town over. When Roy and Gabby arrive in Tombstone, Roy is mistaken for the gunslinger. Just as Roy is ready to expose the mayor, the real gunslinger shows up.
Secret agent Roger Pryor is dispatched below the border to protect an important scientific formula. Believe it or don't, this mixture has the ability to render things invisible.
Roy is a newspaper reporter. He goes to Cheyenne to cover the activities of supposed bad guy Arapahoe Brown. Roy, of course, discovers who the real bad guy is.
On a scientific expedition to Siam young Billy Batson is given the ability to change himself into the super-powered Captain Marvel by the wizard Shazam, who tells him his powers will last only as long as the Golden Scorpion idol is threatened. Finding the idol, the scientists realize it could be the most powerful weapon in the world and remove the lenses that energize it, distributing them among themselves so that no one would be able to use the idol by himself. Back in the US, Billy Batson, as Captain Marvel, wages a battle against an evil, hooded figure, the Scorpion, who hopes to accumulate all five lenses, thereby gaining control of the super-powerful weapon
A group of young men who work at an aviation factory begin to suspect that a doctor who runs an air ambulance service is secretly a spy transporting secret information from the plant to enemy agents.
A test pilot and his weather observer develop a "robot" control so airplanes can be flown without pilots, but enemy agents get wind of it and try to steal it or destroy it.
When the showboat hits town, two men use the parade as a distraction to rob the bank. Their accomplice is Pop, the clown from the showboat. He leaves the money on the boat and tells his daughter Patsy to bring it to him at a later stop on the river. Gene's investigation of a bank robbery takes him to the showboat where he becomes a performer. Gene and Frog try to find the money while helping Patsy and her father.
Muggs is tricked into entering a Civilian Conservation Corps camp by Danny in order to get in shape. Muggs resists and battles with the camp captain and with other campers. He also becomes involved in trying to help one of his friends get out of trouble.
Rightful owner of the kingdom, the Duchess of Zona, is engaged in a power struggle with the evil General Gurko. Edmond, the son of Monte Cristo, dons many disguises to come to the aid of the Duchess.
Wanted by the law in New York, Dr. Steve Kells heads west and arrives in an area controlled by an outlaw gang known as the Border Legion. When the gang's boss is wounded, they kidnap Kells and force him to remove the bullet. Not allowed to leave and being a wanted man, he joins the gang. Now wanted as a gang member also, he nevertheless plans a raid that will lead the entire gang into a trap.
In 1820 Spain, the son of a California nobleman comes home to find his native land under a villainous dictatorship. On one hand, he plays the useless fop, while on the other, he is the masked avenger Zorro.
Trouble in Colorado is tying up Union troops needed back east during the Civil War and Lieut. Burke is sent to investigate. Macklin and his gang are causing the problems and Capt. Mason joins them. When Burke catches up with them he also finds Mason, his brother.
American crime reporter John Jones is reassigned to Europe as a foreign correspondent to cover the imminent war. When he walks into the middle of an assassination and stumbles on a spy ring, he seeks help from a beautiful politician’s daughter and an urbane English journalist to uncover the truth.
While Sam Houston in in the nation's capital trying to get Texas into the Union, his aide is trying to impose a self-serving tax on the use of the Santa Fe trail. The lady owner of a wagon train is using the trail, and a Texas Ranger comes to her assistance.
Sgt. Renfrew and Constable Kelly go aloft to search for a plane missing with a shipment of gold from the Yukon Mine Company. Inventor Speavy has devised a power ray which disrupts electrical impulses, and Morgan and his gang of crooks has brought in Prof. Lewis to increase the ray's range, telling him he's helping the government develop this new weapon. Speavy spills the beans to Prof. Lewis and his daughter Madeleine,and Morgan threatens to implicate them in his crimes unless they cooperate. Morgan kills Speavy when he tries to warn Renfrew, but when Madeleine stows away on board the doomed plane Renfrew is piloting, will the crooks be able to make Prof. Lewis use the power ray to bring the plane down?
In and around some great blues, swing and jazz music, a very unpopular band-leader. Prince Ellis, is killed in a Harlem nightclub, and, in and around some more great music, a detective finds the lists of suspects is very long, as Prince Ellis was indeed very unpopular with many citizens.