 It is an original, studio-commissioned screenplay by Ronald Davidson, produced by Franklin Adreon and directed by Fred C. Brannon, and presents a combined international intrigue–action genres story involving interstate shipments of products critical to national security being hijacked by a gang of foreign agents.Two U.S. government agents, Hal Duncan and Sam Bradley, must prevent agents of a foreign power, led by Regan and Cady, from hijacking trucks and stealing defense materials being transported by truck.They are hired by an interstate trucking association whose constituent truck lines have been principal targets of the hijacking, and it becomes evident that one of the four directors of the association — Armstrong, Crandall, Thompson or Willard — is "the Voice", the secret leader of the gang who provides them with shipment and route information necessary for the gang's successes.