Naina Sethi (Taapsee Pannu) is a young successful businesswoman with a perfect family. Naina’s world turns topsy-turvy when she gets arrested for the murder of her secret lover Arjun (Tony Luke). Her lawyer Jimmy (Manav Kaul) hires prestigious defence attorney, Badal Gupta (Amitabh Bachchan) to defend her, and over the course of one late evening, they work together to find out what actually happened on that fateful day. Badal tells Naina that a witness has landed and it will result in her getting arrested in no time. Naina explains that she and Arjun were blackmailed by someone for their extramarital affair. They were called to a hotel room in a remote location and told to bring money. When they arrive, Naina receives a text from Arjun’s phone saying that the blackmailer is going to reveal the truth. She is suddenly attacked and becomes unconscious. When she wakes up, she finds Arjun dead with the blackmail money scattered everywhere and the police knocking. Naina gets arrested but claims that she did not commit the murder. The police finds no clue of anyone else being present in the room or breaking in. The Allen key, which opens the windows of the hotel rooms, was removed due to heavy snow.
