The story was Kamal Hasan’s idea and is quite fresh - good material for comedy. The story revolves around a group of imcompetant slum-dwellers, lead by Digamber(Vijay Raaz - brialliant as always), who take to kidnapping to raise some quick money. The idea is to kidnap a rich merchant's (played by Shukla, who also wrote the dialogues for the movie) son and demand ransom. But their plan is ill-fated as one of them is hospitalized for an appendicitis operation. The ill man's brother-in-law Avinash (Kamal Hasan) is taken in as a quick replacement. Avinash is an ace motorist who rides his bike in the "Maut-ka-Kuan" (Death-well) and has the earned the epithet of "Mumbai Express". However, Avinash suffers is hard of hearing and is generally clumsy. He also happens to be an innocent youth who has his morals intact. Digamber, desparate to see his plan in action, convinces Avinash to join the team with his half-lies.