Taking its name from a popular series of mystery novels, Inner Sanctum Mysteries debuted over NBC's Blue Network in January 1941. Last broadcast October 5, 1952.Inner Sanctum Mysteries featured one of the most memorable and atmospheric openings in radio history: an organist hit a dissonant chord, a doorknob turned and the famous "creaking door" slowly began to open.Every week, Inner Sanctum Mysteries told stories of ghosts, murderers and lunatics. Produced in New York, the cast usually consisted of veteran radio actors, with occasional guest appearances by such Hollywood stars Boris Karloff, Frank Sinatra, Orson Welles and Peter Lorre.