'Sherlock Holmes' sequel may pit Brad Pitt against Robert Downey Jr.

robertdowneyjr_sherlockholmes_290.jpgA "Sherlock Holmes" sequel? Elementary, my dear Watson.

A "Sherlock Holmes" sequel starring Brad Pitt as the Great Detective's nemesis? Holy [expletive], Sherlock.

Warner Bros. has started work on a sequel to the Robert Downey Jr.-Jude Law take on Holmes and Watson, according to The Hollywood Reporter, with prep including talks with writers and potential co-star Pitt.

Pitt's involvement is intriguing: He'd play Prof. James Moriarty, a London criminal nicknamed "the Napoleon of crime" in Sir Arthur Conan Doyle's stories. Moriarty is often portrayed as Holmes' intellectual equal, though there's no word yet on how that will translate to Guy Ritchie's more action-oriented take on Sherlock.

"Sherlock Holmes" opens in theaters Dec. 25.

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