The world has fallen apart. The leaders of the last remaining civilization believe that for humanity to survive, they need an outlet for their violent nature.
Those inside the Walltowns don't have much of a life (their sole purpose in this new world is to act as whipping posts for those Outside), but Isaac, the Posts' reluctant leader, is doing what he can to keep his community as strong as possible.
When two new arrivals (a teenage girl transferred from another Walltown and an infant born illegally within the Wall) upset the delicate balance of the Posts' survival, Isaac must find a way to protect the lives of everyone he can.
