Mumbai is plagued by a gang of bikers, who rob establishments at will and escape on their souped-up motorcycles. The local police assigns this case to the Assistant Commissioner of Police ACP, Jai Dixit, but he is unable to apprehend the culprits because he is not a mechanic and is not aware of what is involved with customized motorcycles. The only who can assist Jai is a jailbird, Ali Akbar Fateh Khan, who agrees to do so conditionally. Both team up to try to stop this crime spree. They kill one of the bikers, leaving the others to escape. This creates a considerable rift between Jai and Ali and, finally, they fight and decide to go their separate ways. Jai's superiors are not impressed with him, and he decides to resign from his job. Ali, meanwhile, is approached by the leader of the bikers' gang, Kabir, and is asked to join his team, which now has a vacancy due to the death of one of their comrades, Ali agrees to do so. Ali meets the rest of the gang members, including the only woman, the cold-hearted and business-like Sheena, to whom he loses his heart. Meanwhile, Jai has started drinking in a big way, and the police are nowhere close to nabbing the bikers, who now seem unstoppable.
A gang of bikers headed by the cool-headed and arrogant Kabir John Abraham is on a robbing spree in Mumbai. They rob establishments and then zip away on their superbikes. ACP Jai Dixit Abhishek Bachchan is the case in-charge and he recruits a bumbling bike mechanic and racer named Ali Uday Chopra to chase the gang on a bike and help Jai nab them. Kabir accepts the challenge, and pulls off another robbery amidst a function. This causes Jai and Ali to call it off. Jai resigns from the police force and Ali goes back to his daily job. Meanwhile Kabir has lost one of his team members and recruits Ali for their final job in Goa. The action shifts from the congested Mumbai traffic to the sunny Goa for the final showdown between cops and robbers.