 The fiendish Dr. Moriarty is sentenced to death at the Old Bailey. From the dock, he swears that the prosecutor will hang before he does, and that the head of Scotland Yard, and Sherlock Holmes, will also die. Meanwhile, Holmes is in the country, meeting the banker father of his fiancée, to arrange his wedding! Then, the prosecutor is found hanged, and Holmes is told that Moriarty has escaped. Set in England c. 1930, with concessions to American taste as Moriarty imports a gangster to join his band of international master criminals.