Seen through the eyes of a police officer, Once Upon A Time in Mumbaai traces the changing face of the Mumbai underworld. The film, set primarily in 1970-Mumbai, follows the rise of Sultan (Ajay Devgn), and his eventual fall, when his protégé Shoaib (Emraan Hashmi), challenges his supremacy, and usurps power to rule the murky underbelly of Mumbai. IMDB describes the film as, "A tale of two gangsters from the eras of past and present, whose lives enter parallel paths as they struggle to survive within Mumbai's criminal underworld"
