Sherlock Holmes: A Game of Shadows is a 2011 British-American action mystery film directed by Guy Ritchie and produced by Joel Silver, Lionel Wigram, Susan Downey, and Dan Lin. It is a sequel to the 2009 film Sherlock Holmes, based on the character of the same name created by Sir Arthur Conan Doyle. The screenplay is written by Kieran Mulroney and Michele Mulroney. Robert Downey, Jr. and Jude Law reprise their roles as Sherlock Holmes and Dr. John Watson, and several other actors appear as characters they played in the 2009 film. Holmes and Watson join forces to outwit and bring down their most cunning adversary, Professor Moriarty, played by Jared Harris. The film is specifically influenced by Conan Doyle's work The Final Problem, but it is an independent story rather than a strict adaptation. Reviews for the film were generally mixed.