John, you're back into action! A druglord from New York has taken control of important mexican top-secret documents and he's blackmailing the mexican government in exchange of military weapons. Eliminate all resistance and get those documents back!
You and a handful of others form the Last Line of Defense, pooling your remaining stockpile of weapons, special ammo, bunker defenses, and super-weapons to fend off the onslaught by virus infected, bloodthirsty Ravagers.
This is the city of gangsters or let's just say it was the city of gangsters until you came here to clean up the mess and set the people free. Use guns and other weapons to shoot the bad guys down.