Four youthful cadets are implicated in a series of murders, and must attempt to clear themselves of suspicion.

A heavy condensation of the 1936 serial Flash Gordon, with altered musical score. Flash Gordon, Dale Arden and Dr. Hans Zarkov visit the planet Mongo to thwart the evil schemes of Emperor Ming the Merciless, who has set his planet on a collision course with Earth. Released abroad as "Flash Gordon" for countries not interested in booking the serial, and never shown in the USA before 1950, where the title was changed to "Rocket Ship".

Jack Manning (Tim McCoy) arrives in a midwestern town from Gold Creek in Califonia. He brings a message from Goerge Woods (Francis Ford) to his brother Tom Woods (Francis Ford), in a dual role, and niece Mary (Allene Ray, informing them he has struck gold and asking them to join him in California via a wagon train. Jack and Mary fall in love to the great displeasure of Rance Carter (Wilbur McGaugh) who has a yen for Mary himself. Jack and Mary not only have to be wary of Carter's crooked ways and machinations, but also of Indian uprisings, caused by Carter.

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.