"The film begins with the recovery of Simar (Priyanka Chopra) and her husband Nikhil (Arjun Rampal) from a car accident. Simar is almost unscratched but Nikhil has amnesia, along with major physical damage. Simar is determined that Nikhil will get better and resume his life, and brings in the best surgeons to reconstruct his damaged leg and face, and then later helping him with his physical therapy.

Although Nikhil is at first cautious, Simar's love and dedication wins him over. After six months of therapy he is released from the hospital and the couple return home. However, when Nikhil meets up with his old friends and goes through his personal files, he finds evidence that all was not well in his previous life. Now uncertain of his wife's true motives, Nikhil starts retracing his steps from the night of the accident, meeting with his old friend Tanya (Kim Sharma) who tells him that on the night of the accident, he had planned to confront and divorce Simar for infidelity.

Nikhil hires a private investigator named Chamanlal (Saurabh Shukla) who discovers that the accusation is true, and Simar had been having an affair with a man named ""Kabir"". One day Nikhil secretly overhears Simar talking on the phone with Kabir, in which she insists that their relationship is over because she has fallen back in love with Nikhil. However, Simar agrees to meet Kabir one last time. Nikhil follows Simar to a secluded house, where he witnesses an apparent argument between Simar and Kabir. After a chase through the woods, it is revealed that Simar staged the entire thing: Kabir was never on the phone nor in the house, because he has been dead the whole time. Simar confesses that on the night of the accident, Nikhil had found Simar and Kabir together, and in his rage he killed Kabir. Simar wanted to protect Nikhil from the guilt, since she'd believed his amnesia had been a chance to start their relationship anew. Nikhil believes this story, and is temporarily reconciled with Simar.

Nikhil is then contacted by Tanya, who claims that she has some new important information. When he goes to her house, he finds her shot dead. Nikhil informs Chamanlal that he has been having more vivid flashbacks to the night of the accident, and has an idea where Kabir was buried. They drive out and dig up the body, which has been preserved in the snow. However, the corpse's face is exactly the same as Nikhil's.

""Nikhil"" realises that he is in fact Kabir, and had been the one having an affair with Simar. Through flashback, it is revealed that the real Nikhil was emotionally abusive towards Simar. Kabir (Sudhanshu Pandey, but with Arjun Rampal's voice) witnessed Simar being abandoned by Nikhil at a party one night, and picked her up. They began their affair, but after a while Simar became too possessive and obsessed with him. On the night of the accident, Kabir had been trying to leave Simar, who threatened to commit suicide if he did. Just then Nikhil arrived and started a fight with Kabir, which ended when Simar killed Nikhil with her gun. They drove out buried the body in the snow, but on the way back Kabir blamed Simar for the murder and declared that they should go to the police. In the ensuing argument, Kabir lost control of the car, which resulted in the accident at the beginning of the film.

In the present, Kabir is angered that his identity had been robbed by Simar, who took advantage of his amnesia and ordered the plastic surgeons to reconstruct his face in Nikhil's likeness. He and Chamanlal decide to bring Nikhil's body to the police, but are stopped when Simar arrives and shoots Chamanlal. Simar still wants Kabir to accept Nikhil's identity so they can be together, but Kabir refuses. Simar tries to kill them both in another accident so they can be together in death; Kabir manages to escape, but Simar does not.

The final scene is of Kabir arriving at the police station, carrying Nikhil's corpse with him. The end credits begin over footage of Kabir explaining his story to the officers. And officers locked Kabir."