Monahan steadily secured work in the film industry throughout the 2000s. Brad Pitt's production company, Plan B, hired Monahan to write an adaptation of Hong Kong director Andrew Lau's gangster film "Infernal Affairs". Monahan respun "Infernal Affairs" as a battle between Irish American gangsters and cops in Boston's Southie district, and Martin Scorsese directed the completed screenplay under the title "The Departed" for Warner Bros. Monahan's work on the film would later earn him two Best Adapted Screenplay awards, from the Writers Guild of America and the Academy Awards.