Plot

A dynamic young entrepreneur finds herself locked in a hotel room with the corpse of her dead lover. She hires a prestigious lawyer to defend her and they work together to figure out what actually happened.

Naina Sethi a successful entrepreneur finds herself locked in a hotel room.When she gains conscious she finds herself lying to corpse of her lover Arjun she is arrested for the murder.But left on bail her lawyer Jimmy hires a defense lawyer Badal Gupta who hasn't lost a case since last 40 years.Badal and Naina discuss about the events that happened during that day.But Badal feels that there are lot many loopholes in Naina's story.—alex.mjacko@gmail.com

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 defense 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.

Badal gets suspicious that Naina is not being honest with him and says he needs more information to build her case. He takes out the newspaper clipping about a youth named Sunny who had gone missing near the hotel and asks Naina how is she related to it. Naina, then starts narrating her story. The story begins three months prior when she had lied to her husband about travelling to Paris for a business trip and instead went to a cabin outside of Scotland to meet Arjun. At the end of their getaway, Naina feels guilty about lying to her husband and daughter so she tells Arjun that she would like to end their relationship. While driving home, they get into a heated argument about this matter when a deer appears in front of the car and Naina loses control. She hits a car from the opposite direction. The impact kills the driver of the other car (Sunny). Naina panics but Arjun tells her that they cannot call the police if they want to proceed with their life. He convinces her that Sunny wasn't wearing a seat-belt and had been texting so his death was not their fault. They decide to flee but their own car fails to start and a car approaches them. Arjun hides Sunny's dead body and pretends that he is the owner of Sunny's car. When the driver stops to check, Naina and Arjun pretend that they are trading insurance information to deal with the accident. Sunny's phone starts ringing so Arjun answers it and pretends as if he is talking to insurance agents. Once the driver leaves convinced, Naina disposes off Sunny's car in a swamp.

A couple, Rani (Amrita Singh) and Nirmal, stop their car and ask Arjun if he needs any help. Arjun is invited back to the couple's house to get Naina's car fixed. Upon arriving, he realizes that the couple are Sunny's parents, who are worried about their son. Rani calls to Sunny's phone and since Arjun forgot to dispose off Sunny's phone, it starts ringing. Arjun pretends that he had just been sitting on it but Rani and Nirmal are suspicious. Arjun and Naina return home but seeing Sunny on the news channel, they get worried that they will be discovered. Soon, Naina is identified as a suspect in Sunny's disappearance when the couple identifies her vehicle. Naina had already disposed off her car and registers a missing case (fake) in Scotland. This prompts the officials to ask Naina for evidence of her time there. Since Naina was never in Paris, she has Jimmy falsify her alibi and is able to remove her name from Sunny's case. Arjun uses his wife's connections to the bank to make it seem as though Sunny had been stealing money from the bank and had run away. This way, the police no longer believe Sunny had been killed. However, Naina feels guilty and is upset at Arjun's actions. Refusing to believe her son could ever steal, Rani confronts Naina disguised as an economist at a business event. She reveals that she knows Naina had never been in Paris and that Naina is her last hope to know the whereabouts of her son. She also recognizes Naina's lighter, which Nirmal handed back to Arjun when he was leaving their house. Naina refuses to help Rani. A few months later, Naina and Arjun are contacted by a blackmailer. The blackmailer has Arjun throw away his phone prior to showing up at the Glen Moehr Hotel, the site of the murder. Thus, the blackmailer sends Naina a text prior to framing her.

Badal decides that Rani had a motive for killing Arjun and could have easily done so since Nirmal works in the Glen Moehr Hotel (where Arjun was found murdered). He tells Naina that it is quite possible for Rani to have hidden in the room (before Arjun and Naina walked in) and received The Allen key for the window (from Nirmal), allowing a quick escape. They can blame Rani and Nirmal for Arjun's murder and get Naina out of the case. He also suggests to Naina that she should say that she was in Paris, as her records show, on the day of Sunny's murder, which will put the onus on Arjun as the murderer of Sunny. He pressures Naina to reveal the location of Sunny's body as he wants to tie Sunny's death to Arjun. However, Naina, having gained trust in Badal, reveals that Sunny was alive in the trunk before she disposed off the car, but she decided to kill him in order to clear her name. Surprised by Naina's murderous and selfish actions, Badal proposes an alternate sequence of events in which Naina pressurized Arjun into hiding Sunny's disappearance. In this sequence of events, Arjun grows a guilty conscience to the point where he travels to the hotel to reveal the truth to Rani and Nirmal. He sends the text that Naina claims is from the blackmailer, prompting Naina to kill him. With the police knocking, Naina decides to injure herself and blame Rani for the crime. Naina refuses these events and claims that what Badal proposed before was the truth.

Given this story, Badal refuses to fight Naina's case. Naina begs for Badal's help and Badal asks her to honestly reveal whether or not she killed Arjun. Naina confesses her role in Arjun's murder. Despite her guilty confession, Badal agrees to fight her case and reveals that there was no surprise witness. He had simply bluffed to make Naina tell him the truth. Badal then excuses himself in order to take a walk outside. Meanwhile, Naina receives a call from Jimmy. During the call, she realizes that Badal's pen is interfering with the call. When the real Badal Gupta arrives outside her door, Naina takes apart Badal's pen to reveal a voice recorder that had recorded every word of their meeting. She discovers that she had actually been speaking with Nirmal, who had disguised himself as Badal. Rani calls the police and Nirmal quotes the Mahabharata, saying that Draupadi's (Rani's) revenge has been taken by Yudhishthira (Nirmal). The movie ends with another famous quote from Mahabharata, said by Nirmal: "Its not always right to take revenge, but nor is it right to always forgive."