A multitude of new threats, mysteries, and enemies collide to produce a chaotic series of events that forces Dillon Winters to question everything he thought he knew while creating uncertainty about the survival of the human species. After discovering his sister-in-law is pregnant and concerned the baby might be at risk of becoming infected, Dillon Winters ventures outside the security of the compound to uncover the truth behind the infection. In his quest to uncover the secrets behind Cody Pyle's blood, he embarks on a terrifying journey to Colorado, only to stumble upon a new and unexpected threat. One that's more terrifying than the infected. Not only does he have to contend with hordes of infected, marauders, and the constant threat of death, but something just as deadly—if not more so. With time running short, Dillon must confront the harsh reality he finds himself in and discover who his true enemies are and who he can rely on before it's too late.