Reena (Preeti Jhangiani) and fellow collegian Akash Mehta (Dino Morea) are medical (psychiatry)students. They are sweethearts and hope to marry each other after completing their education. Before that could happen, Megha Joshi (Bipasha Basu) enters their lives and changes everything. For Akash falls head over heels in love with her, and will do anything for her. Just when their education is about to get over, Megha disappears from Akash's life for the spectacular task of killing her father to save her mentally challenged mother.

Meanwhile, Aakash becomes a psychiatrist with Reena in the same hospital. Five years later, Megha is admitted in the Psychiatric Ward of the same hospital in a very disturbed condition. She is unable to recollect anything except her last day with Akash, when both had planned to marry each other. Watch how Akash comes to term with his lost love, and promises to do his best to unravel the mystery that is Megha and her equally mysterious disappearance, and her sudden re-appearance in his life. Megha is married to Chandranath Diwan (Irrfan Khan), a very rich drug addict. Megha claims she gets threatening calls and that somebody is trying to kill her.