21st September 2011, a man released a deadly parasite called "The Plaga". The Parasite infecting the city of Los Santos. The city is in a total chaos. The government believe that the people are turning into zombies, but it isn't. They are just an ordinary people. Eat, go to work, every activity that the human does. But when a secret agent, George Ray is sent to find and kill the man, the streets is silent. No one go outside. Now, George is forced to travel around Los Santos, to find and kill the man who responsible for this chaos