City dweller Gabe Common, seventeen and a high school dropout, has just moved with his mother to Chumsville, South Dakota, a speck in the eye of humanity. With a population of around three hundred people, Gabe is resigned to spending his summer studying online and watching the wheat grow.

It all changes when he wakes up one morning and finds most of Chumsville's population gone, including his mother. Along with the other survivors, he finds that an impenetrable barrier has surrounded the town which allows people to enter but not leave. To make matters even stranger, he finds wings growing from his body, and the other residents exhibit changes as well, some of them interesting and many of them frightening.

Soon the Changed, as Gabe comes to call them, are met by the FBI, and they are just as bewildered as everyone else is. Tensions mount as the heat rises, harsh words are exchanged, and sides are drawn. Once Gabe discovers the reason for their transformation, he has to deal with another matter—the darkness of the human heart. It is only then that he learns what it is to confront evil and face it down, even if it might cost him his life.