The film opens with a suicide attempt by Assistant Commissioner of Police ( ACP ) Agnel Wilson ( Randeep Hooda ) on the pretext of the Bombay Bombings in 1993 . When questioned by his superior over his actions , he breaks down and claims that the recent tragic events are his own fault . Wilson recounts that 18 years ago , when he was posted as the ACP in the Mumbai crime branch , his inability to take the necessary action led to the rise of Shoaib Khan ( Emraan Hashmi ) a dreaded gangster , who played a central role in the bombings . Throughout the film , Wilson narrates the story of 1970s Bombay , when it was ruled by a kind hearted smuggler Sultan Mirza ( Ajay Devgn ) , and how Mirza 's eventual downfall led to Shoaib 's rise to power
Bombay Bombings in 1993
1993 Bombay bombings
Once Upon a Time in Mumbaai