Newspaper reporter Sue Walker and her fiancé Lieutenant Jerry Brown of the homicide bureau, are separately investigating a rash of murders connected to the gambling rackets. When the murder of syndicate member Jimmy Clark ignites the feud into open warfare, District Attorney Richard Sutton orders all gambling houses closed. Sutton’s interdiction prompts racketeer Lefty Ross to contact the district attorney with a bargain to expose the ringleaders of the syndicate. However, at a meeting at the district attorney’s house, Lefty is murdered before he can talk, and Sue reports the story, thus embarrassing the police department and her fiancé. Lefty’s autospy shows that he was poisoned by an “invisible killer,” the same method by which the others have been murdered. In her investigation, Sue learns that Cunningham, a real estate magnate and leader of the reform movement, has been leasing property to gambler Vani Martin. When presented with Sue’s evidence, Cunningham is astounded and vows to shut down Martin’s clubs. However, before he can complete his phone call to the district attorney, Cunningham suddenly chokes and dies. Sue grabs the phone and takes it to Jerry. At the police station, they find a poison capsule embedded in the phone and also discover that Jerry’s secretary, Tyler, has been leaking information to the gang. Once again undertaking her own investigation, Sue asks Gloria, Cunningham’s daughter, to talk to Enslee, the mob’s attorney, about her father’s death. Sue’s plan backfires, however, when Enslee, who is actually the ringleader, takes Gloria captive. Sue frantically turns to Jerry for help, and after tricking Tyler into implicating Enslee as the gang leader and revealing the location of his hideout, Jerry and his men rush to rescue Gloria and arrest Enslee. More on Wikipedia or Mubi
Watch The Invisible Killer (1939)
