A mechanic with the French Air Force, Vanesse sabotages the plane of Capt. Charles Nungesser, France's Flying Fiend, by placing Paul Willard's flying insignia in Nungesser's intake manifold. Paul is accused of the deed and sentenced to 20 years in a military prison. Six years later, the Willards, a wealthy American family, arrive in France, searching for Paul, who had run away to war. They interview Vanesse, who informs them that Paul died like a hero in the war. The Willards then meet Nungesser, who falls in love with Lucille, Paul's sister, and makes a silent resolution to arrange for Paul's pardon. This he does, and then goes to the United States to find Vanesse and to discover the truth about Paul's case. Nungesser discovers that Vanesse is planning to rob the air mail; with Paul's help, he captures Vanesse and recovers the loot. Vanesse dies from the effects of a plane crash; Paul is cleared of all guilt and marries his former sweetheart, Marie, with Nungesser and Lucille are swept to the heights on the wings of happiness.