English actor Jared Harris, who plays Lane Pryce on Mad Men, has been cast as Sherlock Holmes’ archenemy, Professor Moriarty, in Warner Bros.’ unnamed Sherlock Holmes sequel, Variety reports. Harris has previously guest starred in the shows Fringe and The Riches, and played tugboat captain Mike Clark in the movie The Curious Case of Benjamin Button. Robert Downey Jr. and Jude Law will return as Holmes and Dr. John Watson, respectively, and Swedish actress Noomi Rapace (The Girl with the Dragon Tattoo) will play the female lead. The sequel, again directed by Guy Ritchie, will be released Dec. 16, 2011.