Robert Downey Jr is "Sherlock Holmes"

In what will be his first job since the blockbuster "Iron Man," Robert Downey Jr is set to star in "Sherlock Holmes," the drama that Guy Ritchie (Snatch) will direct for Warner Bros.

Downey committed to the pic, which begins shooting in October, after Ritchie turned in a polish of the latest version of the script, written by Anthony Peckham.

"Sherlock Holmes" also will take advantage of Downey's physical skills as the character displays brawn as well as brains. The basis for the film is Sir Arthur Conan Doyle's classic tales, but also the comicbook "Sherlock Holmes."

With Downey aboard, the film will go into production before a comedy that just coalesced at Columbia Pictures, with Sacha Baron Cohen playing Holmes, and Will Ferrell playing his crime-fighting partner Dr. Watson.