So Dr richtofen has continued testing on the living subjects and has noticed no change or anything,however he did notice that the zombies had become more and more aggressive . Richtofen doesn't know why.Slowly but surely the zombies were uncontrollable and they broke loose and thousands apone thousands came.Many didn't survive but the ones who did were Dr Edward Richtofen,Taeko,Dempsey and Nikolai.This is were the story truly starts.