Escalation (Green Fields #3)

Is anybody out there?

After a long winter spent hunkering down in Wyoming, Bree, Nate, and the gang are back on the road. The harsh temperatures up in the northern regions might have decimated the undead scourge somewhat, but soon they have to face reality: it’s not just zombies that are out there to hunt people down and kill them. For humanity to have a fighting chance to rebuild a semblance of civilization, everyone will have to work together—and resources are scarce. Someone will have to go out there and face the danger—and maybe find out what happened to the undead that were smart enough to flee the cold. Only the strong and smart have survived, making everyday life just a little more deadly for everyone.

Books in the series (so far):
#1: Incubation
#2: Outbreak
#3: Escalation
#4: Extinction