Something has gone terribly wrong. It started with a sick bat, and a wild boar and a ranch hand named Hector. It exploded into a global crisis. The Texas Wild Boar Flu spread to every corner of the Earth, and people were justifiably terrified. Many died horrible deaths, and scientists from every nation worked tirelessly to create a vaccine. Ten months later, they had one. Humankind was saved. For the moment.

Two years after the first case of Wild Boar was identified, Mike Richards witnessed a shocking act of violence, random and unprovoked. It was not the last, and all the incidents he witnessed were perpetrated in a cooly deliberate manner by calm and emotionless attackers. They appeared unperturbed by their actions, and the motivation behind their attacks was unclear.

Richards soon finds himself far from home in an unfamiliar city as things really start to fall apart. He joins forces with a young nurse to flee the violence, but there appears to be no safe place to run. They face threats at every turn, not just from strangers, but from friends, colleagues and family members. It is impossible to know who to trust. To survive, they must be prepared to do the unthinkable.