Directors: Colbert Clark, Albert Herman
Cast: Bela Lugosi ... Professor Strang Viva Tattersall ... Vera Strang Malcolm McGregor ... Jack Foster Henry B. Walthall ... J.D. Bradley Robert Warwick ... Detective Raymond Ethel Clayton ... The Countess Helen Roy D'Arcy ... Professor Steinbeck Karl Dane ... Sparks Lloyd Whitlock ... Young Bob Kortman ... Jasper Slade Lafe McKee ... D.W. Jerome
Seeking to avenge the killing of his brother Jack Foster works tirelessly with Detective Raymond to unmask THE WHISPERING SHADOW, but who is this mysterious criminal and technological genius who uses radio waves to kill and orders his henchman through strange television broadcasts? And what is he after in the warehouse of the Empire Transport and Shipping Company? Find out in this exciting twelve chapter Mascot serial!