The Sign of Four

Ian Richardson stars as Sherlock Holmes, who teams up with Dr. John H. Watson (David Healy) to track down the Great Mogul, the second-largest diamond in the world. They are aided in their search by Major John Sholto (Thorley Walters), while they also uncover a treacherous plot involving the theft of the Agra treasure, which is hidden in the wooden leg of a suspect named Jonathan Small.