The Private Life of Sherlock Holmes is a 1970 British-American film directed by Billy Wilder and starring Robert Stephens as Sherlock Holmes and Colin Blakely as Dr. John Watson. The film is set in London in 1887 and 1888, and features two separate cases which eventually merge into one.
The first case involves a beautiful woman named Gabrielle Valladon (Geneviève Page) who comes to Holmes and Watson seeking their help in finding her missing husband. As they investigate, they discover that her husband was keeping a secret laboratory and was involved in some kind of illicit activity.
Meanwhile, Holmes is also dealing with his own personal demons and is plagued by flashbacks of his childhood and early years as a detective. He is also struggling with his feelings for Gabrielle, who he finds himself increasingly attracted to.
As the investigation progresses, Holmes and Watson travel to Scotland to investigate the mysterious disappearance of a group of six midgets. Their investigations lead them to a castle owned by a group of villainous monks who are involved in a sinister plot to steal a secret British Naval device.
Finally, Holmes and Watson travel to Loch Ness, where they encounter the legendary monster and uncover the truth behind the naval experiments. In the end, they solve both cases and Holmes is left to come to terms with his own personal issues and the consequences of his actions.