Mr Joe B. Carvalho (Arshad Warsi) is your (slightly below) average coy-go-lucky private eye in the quest for a truly challenging case that can bring in money and fame and change his fortunes for good. A moneyed Khurana (Shakti Kapoor) hands him a case to find his eloped daughter.
Meanwhile Joe’s ex-girlfriend Inspector Shantipriya Phadnis (Soha Ali Khan) is chasing an inteational criminal Carlos (Jaaved Jaffrey) a lollypop-sucking inteational terrorist who is in town with a big murder plot. A local underworld don MK (Vijay Raaz) has been roped in to help Carlos but with intentions of killing him.
The detective-inspector-don ends up in the terrorist’s hotel room and Joe is mistaken as Carlos. Both MK and Shantipriya are now on his trail, whereas clueless Joe ends up spying on a wrong girl. This starts a conspiracy that is enough to drive every one crazy.