It was a lot of money. The three-member gang [Vijay Raaz and his friends] had a plan, an ingenious one at that, of kidnapping a millionaire's [Sourabh Shukla] son from his school. They fell short of a man. They chose one. He had a strange name... Mumbai Xpress, but that was his working name. His original name was Avinash [Kamal Haasan].

Avinash didn't want to flirt with crime. He wanted to be a law-abiding citizen. Unfortunately, the plan goes haywire when they kidnap not the millionaire's son, but the son of an A.C.P. [Om Puri] and his mistress Ahilya [Manisha Koirala].

What follows are hilarious situations, mistaken identities and a comedy of errors.