 Narrator Jack Webb informs us that there are several places behind the Iron Curtain used for training Soviet espionage and sabotage forces prior to infiltrating America.Webb introduces us to a typical American family of father Jerry (Jack Kelly), wife Helen (Jeanne Cooper), and daughter Linda (Patricia Woodell, the original Bobbie Jo on "Petticoat Junction") Donovan.Her boyfriend Bill Martin (Peter Brown) has been invited to dinner but while Jerry lectures Bill on football plays, Bill only has eyes for Linda.