Mumbai police commissioner Prakash Rathod (Anupam Kher), resting after a jog, describes in a voice-over that he is going to retire the following day. He goes on to describe the most challenging case he faced in his career.
An unnamed man (Naseeruddin Shah) carries a travel bag, assumed to contain explosives, in the Chatrapati Shivaji Terminus railway station and proceeds to hide the bag in the restroom of a police station opposite to the Mumbai Police headquarters. He then arrives on the rooftop of a building under construction where he has set up his base of operations, equipped with several sim cards, mobile phones and other electronic gadgets. He calls Rathod and informs him that he has placed five bombs in locations throughout Mumbai and has programmed them to explode simultaneously within four hours unless the Commissioner gives in to his demands and releases four militants. Rathod immediately alerts his team involved in intelligence research and surveillance, tapping all the available resources to trace the location of the caller. Meanwhile, the caller tips off television news reporter Naina Roy (Deepal Shaw), telling her to reach the police headquarters immediately as it is going to be “the most important day of her life”. Rathod initially suspects the anonymous caller is bluffing, but his doubts are dispelled as the caller, to prove his seriousness and the police force’s helplessness, reveals that a bomb has been planted in the Colaba Police Station right across the Police Headquarter. He further scares them by calling the cell phone attached to the bomb but does not detonate the bomb. Just then Roy reaches the scene on the caller’s instructions and reports about the situation.