Shivani Shivaji Roy (Rani Mukerji) is a senior inspector crime branch, in Mumbai. She lives with her husband Dr. Bikram Roy (Jisshu Sengupta) and her little niece Meera which she is very protective of. Clever at picking up hidden clues and fearless in confronting hardened criminals with wild chase, 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 the mafia kingpin smuggled the girl outside the city. The mafia kingpin Walt calls Shivani and wants to know what she wants, so she will stop chasing them. Shivani asks the mafia kingpin/Walt (Tahir Bhasin) to let Pyari free, but he won't let her free, because Pyari has seen too much. Shivani Shivaji Roy doesn't know the name of mafia kingpin and she challenges him that she is going to catch him in 30 days and what follows is a cat and mouse game between a young, ruthless mafia kingpin and police.