AllMovie

This drama of international crime and intrigue was based on the famous series of novels by Louis Joseph Vance. Jack Holt plays gentleman crook Michael Lanyard, also known as the Lone Wolf. The United States government has developed a ray that can stop an airplane engine in midair, but the plans, hidden in a deck of cards, are stolen. A ring of crooks known as the Pack find out that Eckstrom (Alphonse Ethier) has the plans and goes after them. One of the gang, Lucy Shannon (Dorothy Dalton), meets Lanyard and suspects that he is the Lone Wolf. Lanyard has gone to the American Embassy and offered to get the plans back, but only if the United States will allow him to live, unmolested, in America. One of the Pack gets the plans from Eckstrom, but Lanyard knocks him unconscious and steals them. He removes them from the deck of cards and secrets them away in a cigarette. Lucy has decided to help Lanyard and they plan to escape together, but the Pack finds them together, and Lucy pretends she is still on their side by holding Lanyard at bay with a revolver. Lanyard lays the deck of cards on the table and the gang takes them. Eckstrom, however, knows better and demands the cigarette. He takes off in a plane and Lanyard and Lucy pursue him for a dramatic fight in the air. Only after they get the plans and return to earth does Lanyard find out that Lucy is actually a member of the Secret Service.