Shivani Shivaji Roy (Rani Mukerji) is a senior inspector of the criminal branch in Mumbai. She lives with her husband, Dr. Bikram Roy (Jisshu Sengupta), and her little niece, Meera, of whom she is very protective. Clever at picking up hidden clues and fearless in confronting hardened criminals after wild chases, Shivani takes on a case that changes her life. A teenage girl, Pyari, who is like a daughter to her, is kidnapped by the trafficking mafia and smuggled out of the city. The mafia kingpin, Walt, calls Shivani and wants to know what she wants, so she will stop chasing them. Shivani asks Walt (Tahir Bhasin) to let Pyari free, but he won't let her free, because Pyari has seen too much. Shivani doesn't know the name of mafia kingpin and she says that she is going to catch him in 30 days. What follows is a cat and mouse game between a young, ruthless mafia kingpin and the police...