As the survivors race to find a way out of the city, they encounter unexpected challenges and startling revelations that shatter their understanding of the situation. There's more to this outbreak than the government let on, and it's far deadlier than anyone ever could have anticipated.In their desperate attempt to stay alive, the survivors are forced to make difficult decisions that will put their humanity and morality to the test. Trapped in their predicaments, they are faced with a terrible realization.The infected aren't the only threat.