DAVID HARDING, COUNTERSPY: Based on the popular 1942-1957 network radio series created by Phillips H. Lord. Howard St. John is the Washington DC-based David Harding, head of a covert counter-espionage organization, charged with preventing top-secret scientific information from reaching the hands of America's enemies around the world, and trying to convince a hell-raising radio correspondent to join the fight. DANGER ZONE: When you deal with dames, you are in the Danger Zone, as the character of crime detector Dennis O'Brien (Hugh Beaumont) learns in his inaugural mystery-drama. The private eye first cracks a case involving smuggling ring, then tackles an assignment that involves blackmail, murder and film noir's top bad guy, Tom Neal. THE BIG CHASE: As his expectant wife (Adele Jergens) enters the hospital in anticipation of the blessed event, cop Glenn Langan is off to the races, trailing payroll robbers (including Jim Davis and Lon Chaney Jr.) on a mad chase that goes from cars to rowboat to motorboat to helicopter. The chase sequence, captured in all it's bullet-to-bullet glory, comprises a third of the movie.