Set in the Victorian Age and regarded by many as the finest of the fourteen films in the Sherlock Holmes/Basil Rathbone series, The Adventures of Sherlock Holmes was originally released in 1939 by Twentieth Century-Fox.
Professor Moriarty (George Zucco) has at long last been brought to trial for murder, but the Napoleon of Crime is acquitted after the court finds a lack of sufficient evidence. Moriarty wastes no time in plotting his next crime, but in order to be successful he must divert the attention of the Great Detective.
Intimidating, anonymous letters sent to young socialite Ann Brandon (Ida Lupino) ; the murder of Miss Brandons brother; and threats to the security of a priceless gem consume the attention of Sherlock Holmes (Basil Rathbone) and his companion Dr. Watson (Nigel Bruce).
Are these mysterious occurrences simply erroneous distractions? Are they clues to a case irrelevant to the exploits of the evil Professor Moriarty? Or, are these portents of disaster inexorably linked to the master criminals plan to commit a crime that will shake the very foundation of the British Empire? It is for Holmes and Watson to sort out these mysteries and, hopefully, eliminate the menace of Professor Moriarty.