In a world where Thinkers control the population and Rules are not meant to be broken, fifteen-year-old Violet Schoenfeld must make a choice to control or be controlled after learning truths about her "dead" sister and "missing" father.

After being captured and surgically transformed into a "special," teenaged Tally Youngblood, now a government agent programmed to protect society from outside threats, is ordered to eliminate the rebel colony New Smoke, Tally's former home.