Mumbai is baffled by a series of Internet thefts. Among the victims is Babu Anna (Akhilendra Mishra), an underworld don, who wants revenge.
Jai Malhotra (Shahid Kapoor) lives with his best friend, Sonia (Kim Sharma). He meets Neha Mehra (Kareena Kapoor) and falls in love with her instantly. At first Neha rejects Jai, causing him to attempt suicide but later, she accepts him.
Neha later tells Jai that her father owed money to Babu Anna's gang. To repay the amount, he became part of a gang of criminals who were responsible for the Internet thefts. After his death, the gang is now pursuing Neha.
Determined to help her, Jai tries to rob Vikram Singh (Fardeen Khan), but gets caught. Vikram, who is also part of the gang of internet thieves agrees to help Jai on the condition that he takes the blame for the Internet thefts. Jai agrees, gives the money to Neha and turns himself in.
When Babu Anna finds out that the thief has been found, he tries to capture Jai, who escapes. With both the police and the underworld after him, Jai goes to Neha's apartment. He finds Vikram there and realises that he has become the fall guy for them both. He escapes from the apartment, but is shot and presumed dead.
One month later, Neha and later Vikram start getting anonymous phone calls. Neha believes that the calls are from Jai and that he is still alive. Jai, who is very much alive is bent on getting revenge on both Neha and Vikram. Jai even tries to kill Neha who is saved by Vikram who later tracks him down and severely beats him up. After a cat and mouse game, the film ends with Vikram finally killing Jai. Before dying, Jai shoots Neha fatally in the head. After Neha's death, Vikram donates a large amount of his money to charity.