International crook Michael Lanyard, alias "The Lone Wolf," offers to recover stolen plans for a defense apparatus in exchange for asylum in the United States. He meets Lucy Shannon, a member of the gang, called "The Pack," suspected of having the stolen plans. Lucy assists Lanyard in obtaining the plans and later helps him escape from the other members of the gang. Together, in a daring airplane ride, they deliver the plans. Lanyard learns that Lucy is a Secret Service agent.