Naina Catherine Kapur (Preity Zinta) is a beautiful introvert, uptight MBA student whose life changes when she meets her charismatic new neighbour, Aman Mathur (Shah Rukh Khan). The duo fall in love, but a dark secret prevents Aman from reciprocating Naina's feelings.When Naina learns about Aman's past, she ends up marrying her best friend, Rohit Patel (Saif Ali Khan), who too loves her. But when the truth unravels, Naina is left shattered and heartbroken.