Mickey Lofton, young half-brother of famed war-aviator Jerry, fails in his attempt to enter the Canadian Air Corps, because of his fear of thunderstorms developed by an incident in his boyhood days. Jerry, now a Captain in the U.S. Department of Justice, is given an assignment to capture some border oil smugglers. Through his friendship with Raoul McGuire, one of the suspects, Jerry is accepted as a member of the gang. Mickey is in love with Raoul's sister, Molly. Gang leader Moran shoots and wounds Raoul, and is himself shot down by Jerry. Mickey flies Molly and her wounded brother to a hospital. Jerry takes off in another plane to guard Mickey's craft from a pursuing airplane, and crashes his plane into the gangster's plane but parachutes to safety.