Erskine (Efrem Zimbalist goes undercover in Dallas to smash up a spy ring. At the same time, Lee Barrington (Steve Forrest), who is unhappily married to the daughter of a nuclear research plant owner, falls in love with Joanne Kinston (Diana Hyland). Little suspecting that Joanne is actually an enemy agent named Marie Roska, Lee tries to win her love by stealing nuclear secrets and selling them to the highest bidder--and Erskine may not be in time to stop him. ~ Hal Erickson, All Movie Guide