Sam (Hina Khan) works at a magazine company, she has a neighbor Vivek (Rohan Shah) who has a crush on her. Sam has a very fragile relationship with her boyfriend a film director Om Kapoor (Sid Makkar) as he reciprocates feelings whenever he likes.
Sam has a birthday party at her apartment where all her friends and colleagues are invited, she is broken when Om doesn't attend the party, Vivek helps clean the apartment and Sam suddenly breaks down and reveals about Om to Vivek in a drunken state. Vivek tries to console her and in the process Sam kisses him. Vivek then reciprocates and they have passionate sex.
Next morning Sam wakes up and is shocked to see Vivek sleeping next to her. Om rings the doorbell and Sam get worried, Vivek says its ok to which Sam says she will talk to him later.
Sam is still thinking about the previous night in the office meeting to which her boss shouts at her for being absent minded in the meeting, this is heard by Vivek who is outside, he gets food for Sam and sends everyone else for lunch. Sam is disturbed and warns Vivek that last night was a mistake, and warns him from interfering in her personal life.
Next day Sam sees that she is not able to enter her office, her boss then informed her that the company files have been hacked from her laptop to which Sam says she has no clue how that happened. Vivek then calls Sam and reveals that he hacked the company files to teach Sam's boss a lesson. (Vivek had previously hacked into the police records and uploaded a mobile vendors name as most wanted just because he refused to repair Sam's phone)
Sam calls Vivek to a cafe and tells him to revert what he has done. Vivek reveals that he loves her and can do anything for her to which Sam slaps him in front of everyone and warns him to stay away from her.
Rest of the story is how he ruins her life by taking control of it by bugging her house and making her life miserable.
It is then revealed that he has spoiled other girls lives as well just because they had rejected his love.
In the end Sam takes revenge by killing him just after he wipes all the evidence which would prove that Sam killed him.
The case is closed and police doesn't have any evidence of who killed Vivek. Sam is shown walking out of the office with her neighbor and childhood friend Rohan Mehra (Mohit Malhotra) seeming showing that Sam has started a fresh life with him.