Karan (Sonu Sood) loves Sneha (Tanushree Dutta) but is too introverted to ever express his feelings to her. Although Karan’s feelings are evident to many, he is content in just seeing Sneha smile and never gathers the courage to tell her how he feels. On an occasion Karan invites Sneha to a party where she meets the charming and mischievous Vicky.
Vicky (Emraan Hashmi) is Karan’s childhood friend. The exact opposite of Karan, Vicky is an extrovert and a notorious flirt. All three lives change when Vicky joins Karan and Sneha in college, and Sneha begins feeling drawn towards Vicky. However Vicky is not convinced of Sneha’s feelings. To prove her love towards Vicky, Sneha decides to seduce Vicky and both make love. In the morning , Sneha confesses to Vicky that she loves him truly and previous night should end any of Vicky’s doubts once and for all.
Fearing Vicky’s intentions, Karan tries to talk him out of his relationship with Sneha, but Vicky assures him that this time he really is in love with Sneha and not flirting. Karan feels he has lost the only woman he has ever loved but knows he cannot do anything about it. However, life goes on and the three of them share a special bond of friendship. Vicky also tries to help Karan with his love life by setting him up with another college friend, Chandni.
Everything seems to be going well between the two, an incident one night shatters them, where Vicky is caught cheating with Chandni. Things change, trust is broken, obsession and confusion ensue and Sneha is heartbroken and taken aback. Vicky tries to talk to Sneha but Karan intervenes and fights with him. Sneha breaks them apart but takes Karan’s side. Vicky parts from them but claims Sneha will always be his. One night, Sneha is left in a paranoid state after Vicky appears to call and maliciously text her followed by pounding at her door and throwing a rock through her window, with a message claiming Sneha as his own. Sneha then turns towards Karan for support. Vicky is later shown getting thrown in jail for handling drugs. Over time, Karan finally musters the courage to propose to Sneha with the willingness of her father.
The night Sneha and Karan get engaged, Vicky is bailed out of jail and re-enters their lives, bringing Chandni along with him. Vicky gets Karan to confess the truth to Sneha of what really happened. It turns out that Karan could never get over liking Sneha nor his jealousy towards Vicky. After walking in on them, Karan decides to have Vicky entirely removed from both their lives and begins to frame him in order to win Sneha’s trust. It is revealed that Karan set Chandni up to drug and seduce Vicky at a time Sneha would catch them together. Karan later steals Vicky’s phone and harasses Sneha with it, followed by himself pounding on her door and throwing the rock through her window. Knowing that Vicky kept drugs for a friend, Karan tips the police to have him arrested.
Sneha is shocked and horrified at Karan’s misdeeds, saying that she now hates him. Karan then attempts suicide by pointing a gun to his head. As Vicky and Sneha try to stop him, Karan fires a shot in Vicky’s direction but instead kills Chandni. Vicky and Karan engage in a bloody fight which ends with themselves and Sneha severely wounded and unconscious. All three are hospitalized as authorities investigate all those incidents. In the end, Karan is arrested for Chandni’s murder but apologizes to Sneha and wishes her all the best on his way out. Sneha later reconciles with Vicky and they both profess their love for each other.