A thriller set against the backdrop of the battle between the Mumbai mafia and cops, Enemmy is the story of four intrepid CID officers (Suniel Shetty, Kay Kay Menon, Johny Lever and Mahaakshay), who are entrusted with the responsibility of cracking down on the underworld and cleaning up the city by any and all means possible.
When the four cops initiate an investigation and manage to nab Mukhtar Memon (Zakir Hussain), a crime lord, everyone heaves a sigh of relief. However, the relief is short-lived and after a brief spell of peace, the gang wars start again, shocking everyone.
Deciding to up the ante, the dynamic political leader R.G, who had unleashed the CID sleuths, sends in a CBI officer (Mithun Chakraborty) to Mumbai to get to the bottom of things. However, what the officer discovers is that the gang-war is merely a faÃ§ade to find out about a heist, in which two truckloads of hard cash were stolen from Memon, who will stop at nothing to get his money back.
The question is... who is crazy enough to steal from the king of the city underworld? Thus begins a cat-and-mouse game between the characters of the film that keeps the story line interesting right to the logical end of the film.