Adam, Natalia, and Henry weren't just close friends. They were the last crew of the International Space Station. Forgotten by all but a few survivors, they helplessly watch as the world below them is consumed by the infected dead. As they circle the Earth from orbit they are forced to survive in space until a time when they no longer have a choice, but when they return, it's not to the same world they left behind. The world has had years to change. The infected dead roam the streets and the forests in search of living victims. No one knows how the virus started, but even less is known about how to stop it. All the survivors can do is try to outlive it. Cities have fallen before the hordes of infected, but a small band of survivors has fought back by locating and liberating a network of shelters built by the government during the Cold War. Their goal is to unite enough survivors to eventually turn the tide of death in the favor of the living.