From The Arthur Conan Doyle Encyclopedia
James Mason (15 may 1909 - 27 july 1984) is a British actor who played Dr. Watson in 1979 in the British-Canadian movie Murder by Decree with Christopher Plummer as Sherlock Holmes. Laurence Olivier should have played Watson, but the project was abandoned because he didn't like Peter O'Toole who should played Holmes. James Mason was therefore one of the few actors that director Bob Clark contacted to play the role. He even travelled to Spain to offer him the role, on the set of another film. Mason agreed to play Watson on one condition: if he could flesh out the character and especially avoid holding the role of stooge idiot (he remembered the interpretation of Nigel Bruce). It was accepted and Mason could even rewrite two scenes including the, famous, green pea "crushed" in the plate.