Police Commissioner Suryadev Singh (Amrish Puri) looks after his granddaughter Kajal (Twinkle Khanna) after her parents were poisoned by his enemies. Suryadev's cousin Vishambar (Suresh Oberoi) is plotting the complete ruin of Suryadev, along with wife and brother in-law Bhanwari (Shakti Kapoor), because Vishambar's late father had given his share of property, including a village Sundernagar, to Suryadev as Vishambar married someone against his wishes. Vishambar plans to kill Kajal to avenge himself as with Kajal gone, his son Nagendra can inherit the property. He hires Karan (Ajay Devgn) for this, a young man in need of money for treating his ailing mother in hospital. By rescuing Kajal in a fake kidnapping drama enacted by Vishambar's goons, he wins Suryadev's confidence. Suryadev then sends Kajal to some relatives in his village for a while, with Karan as her bodyguard, convinced that he will protect her.
Kajal falls in love with Karan, but he does not reciprocate. He hesitatingly tries to kill her on many occasions. Finally Karan decides to tell her everything, but Kajal refuses to listen and woos him till he finally gives in. Interspersed between is Damru (Johnny Lever) and his girlfriend with their hilarious acts. Vishambar learns that Karan has fallen for Kajal, and hires another killer, Dilavar to eliminate both of them. Kajal is kidnapped, but Karan rescues her and kills Dilavar.
Suryadev learns of Karan's original motive from a note written by Karan for Kajal, before he falls for her, left in his room, which she never reads. The lovers are finally apprehended. Karan is tortured, but does not reveal who hired him to kill Kajal, for fear that his mother would be affected.
Suryadev then arranges for Kajal to be married to Rohit, son of his longtime friend. Kajal agrees on the condition that Karan will be released from custody, to which Suryadev agrees. Karan learns about Kajal's wedding plans and leaves enraged, Karan's mother and Rohit are kidnapped by Bhanwari, and Karan is called to kill Rohit if he wants his mother back. Karan rescues Rohit and his mother, killing Bhanwari and his men. But Suryadev thinks Karan is behind kidnapping Rohit, and gives orders for him to be shot at sight.
Karan and Rohit arrive at the wedding scene, and Karan insists Rohit marry Kajal. A dying Bhanwari informs Vishambar about what Karan has done, and enraged, he fires a machine gun indiscriminately as Rohit is being married to Kajal, but Karan kills him. As the police take Karan away, Suryadev promises him a quick return from jail and marriage with Kajal.
