In the suburbs of the city exists a genetic research facility called the Dive,owned by the Orange Corporation. A thief steals the genetically engineered T-virus and contaminates the Dive with it. In response,the facility's artificial intelligence,the Red King,seals the Dive and kills everyone inside.
Now all the people in this facility turns into zombies and even ones who you ever worked with or fell in love with. For the safety of the whole city,you need to clear those zombies and stop T-virus from spreading.