When World War I comes to an end, three pilots find themselves on hard times. They wind up in Hollywood, where they work as stunt fliers for a sadistic director.

Nearly 7,000 Curtiss Jennies were built and they had a long and distinguished career in the movies. In this load of garbage, a Swahili village (somewhere in the sierras behind Hollywood) is affected by disease. The nearby diamond mine is using this as an excuse not to ship diamonds back to HQ in South Africa. The mine president has sent a doctor, his beautiful daughter and her duenna to find out what is going on and to cure the natives. They are travelling on foot. To speed things up the president sends his ace flyer up...

Special agent Al Langdon pursues elusive gem smuggler Michael Revere. Going undercover, Langdon joins Revere's gang, and in this capacity is obliged to rescue their beautiful hostage, Mary Lacy.

Dick Morgan, formerly a professional crook, returns from the war as the "Ace" of his squadron.