Robert Castleback is in possession of secret papers which could bring a certain prince to power under conditions which would make Castleback a ruling force in Europe. Master crook Arsene Lupin becomes aware of Castleback's bid for power and, in the interests of France, begins a search for the plans.

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.

Bullfighter Juan Gallardo falls for socialite Dona Sol, turning from the faithful Carmen who nevertheless stands by her man as he continues to face real danger in the bullring.

In Arizona a young woman who's being manipulated by an evil businessman is helped by the Cisco Kid who happens to be there on holiday.

When two showgirls decide to leave South America and head for home, they sweet talk the purser of a clipper ship into giving them berths. In the course of the voyage, a band of thieves attempts to take over the ship and make off with its cash cargo. The heroic purser has other ideas and weighs in to save the day.

Soon after a Chinese princess comes to the US to buy planes for her people, she is murdered by a poison dart fired by an air rifle.

On faraway Mosaque, an American pilot finds that he is in a desperate struggle with a military officer intent on sabotaging a local fort.

Cisco and Gordito arrive to find there is an outlaw operating in the area who is assumed to be the Cisco Kid. When a reward is offered for his capture and a large shipment of money goes out, Cisco is on hand. Seeing the gang rob the stage he goes after them only to be wounded. The gang leader leaves Cisco's handkerchief at the scene and now he is wanted for the murder he tried to break up.

Tom Joad returns to his home after a jail sentence to find his family kicked out of their farm due to foreclosure. He catches up with them on his Uncle’s farm, and joins them the next day as they head for California and a new life... Hopefully.

The Kid and his pals are horse thieves wanted by the law. As he takes a horse from Jan Walton she makes him promise to bring it back.