| Director | Sujoy Ghosh |
|---|---|
| Genre | crime thriller film |
| Country | India |
| Budget | ₹10 crore |
| Box office | ₹138.5 crore |
Naina Sethi is a sharp, ambitious young businesswoman in London with a seemingly perfect life, until her world is turned upside down when she's arrested for the murder of her lover, Arjun. Her lawyer, Jimmy Punjabi, hires renowned defence attorney Badal Gupta to help, and over the course of one evening, they work to uncover what really happened. Badal informs Naina that a witness will testify against her. Naina explains that she and Arjun were being blackmailed over their affair. They were summoned to a hotel, where she was attacked and later woke up to find Arjun dead, along with the money they had brought for the blackmailer. Although arrested, she's currently out on bail. The police found no evidence of anyone else being in the room or breaking in.
Badal suspects Naina is withholding the truth and presses her about the disappearance of a young man near the hotel. Naina then admits that a few months earlier, she and Arjun had gone to a cabin in the woods. On their way back, she accidentally hit another car, killing a young man named Sunny. Arjun convinced her not to report it (since Sunny had been texting while driving and not wearing his seat belt), and they covered up the accident. They put Sunny's body in his car's trunk, which Naina later dumped in a swamp. As Arjun waits for Naina in her car, an elderly couple Rani and Nirmal pass by the car. Nirmal offered to fix the car at their home, while Rani invited Arjun in to have tea. As he talks to Rani, he learns from a picture of Sunny in their house, that he is their son. Rani grew suspicious when she heard her son's phone ring in Arjun's pocket, as he had forgotten to get rid of it. Moreover, it worsened when Arjun is seen adjusting the driver's seat after the car was repaired. Arjun picks up Naina, details his encounter with the couple and Naina dumps in the car in a dump yard, reporting it to be stolen. The two part ways afterward.
Naina later saw news reports accusing Sunny of embezzling money from the bank where he worked before disappearing. She realised that Arjun had taken Sunny's wallet and used his wife's credentials to hack the bank and frame Sunny. Through the number plate, Rani identified Naina's car at the time of her son's disappearance, but Jimmy falsified an alibi. Although the police accepted it, Rani wasn't convinced. She confronted Naina at an event where she was awarded the ‘Businesswoman of the Year’. Rani begs her to reveal Sunny's whereabouts, but Naina kept up her lie. Months later, she and Arjun were contacted by a blackmailer, leading to the events that got her arrested.
Badal theorises that Rani killed Arjun, with Nirmal's help since he worked at the hotel. Naina admits she saw Rani in the room but had lied to test Badal's competence. Badal then reveals that there was no witness—he had made it up to get the truth from her. In order to place the blame on Arjun, he convinces Naina to reveal the location of the swamp where Sunny's car was dumped; a belonging that was specific to Arjun would be placed to make Naina appear innocent in the act. Now trusting him, Naina confesses a dark secret: Sunny had still been alive in the trunk when she dumped the car, but she chose to let him die to avoid getting caught. Shocked by her actions, Badal suggests that Naina, not Arjun, orchestrated the cover-up and framed Sunny. He speculates that Arjun, overcome with guilt, went to the hotel to confess to Rani and Nirmal, and Naina killed him to keep the truth hidden. Naina denies this, insisting that her earlier story is the real one.
Badal refuses to defend Naina any further unless she admits to killing Arjun, which Naina does. Badal agrees to continue helping her, but steps outside to call his wife about his overtime work on this case. Meanwhile, Naina receives a call from Jimmy and notices that Badal's pen is disrupting the signal. Realizing something is wrong, she discovers that the man posing as Badal was an imposter when the real Badal Gupta arrives at her door. Horrified, Naina disassembles the pen, revealing a hidden voice recorder with her confessions. She looks out the window and sees the imposter and Rani in the apartment across from hers. The man posing as Badal removes his disguise, revealing himself to be Nirmal. With solid evidence backing her up this time, Rani then calls the police to have Naina arrested.