Thalli has fifteen minutes and twenty-three seconds left to live. The toxic gas that will complete her annihilation is invading her bloodstream. But she is not afraid. Thalli is different than others in The State. She feels things. She asks questions. And in the State, this is not tolerated. The Ten scientists who survived the nuclear war that destroyed the world above believe that emotion was at the core of what went wrong—and they have genetically removed it from the citizens they have since created. Thalli has kept her malformation secret from those who have monitored her for most of her life, but when she receives an ancient piece of music to record as her community’s assigned musician, she can no longer keep her emotions secreted away. Seen as a threat to the harmony of her Pod, Thalli is taken to the Scientists for immediate annihilation. But before that can happen, Berk—her former Pod mate who is being groomed as a Scientist—steps in and persuades the Scientists to keep Thalli alive as a test subject. The more time she spends in the Scientist’s Pod, the clearer it becomes that things are not as simple as she was programmed to believe. She hears stories of a Designer—stories that fill her mind with more questions: Who can she trust? What is this emotion called love? And what if she isn’t just an anomaly, but part of a greater design?

She was an anomaly with a death sentence. Now she's free. Thalli was scheduled for annihilation. She was considered an anomaly—able to experience emotions that should have been eradicated by genetic modification. The Scientists running the State couldn't allow her to bring undue chaos to their peaceful, ordered world. But seconds before her death, she is rescued. Now Thalli is above ground in a world she thought was destroyed. A world where not even the air is safe to breathe. She and her three friends must journey across this unknown land, their destination a hidden civilization. It's their only chance of survival. Broken and exhausted after an arduous journey, they arrive in New Hope, a town that survived the nuclear holocaust. When Thalli meets the people there—people actually "born" to "families"—her small world is blown wide open. Soon after their arrival to New Hope, the town comes under attack. She has escaped imminent death, but now Thalli is thrust into a new fight—a fight to save her new home. Does she know enough about this world of emotions, this world of chaos, to save not only herself, but the people she has come to love?

All her life Thalli thought she was an anomaly. Now she must use her gifts to fulfill the role she was called to play: Revolutionary. Back in the underground State against her will, Thalli is no longer the anomaly she was before. She has proven herself to be a powerful leader aboveground and returns with information that Dr. Loudin needs to complete his plan of uniting the world under one leader: himself. But he, too, has information. A secret he has kept from Thalli her entire life. A secret that, once revealed, changes everything about the person Thalli thought she was. Hoping to help Thalli rise up against the Scientists, both Berk and Alex join her underground, but their presence only brings more trouble for her. Now Dr. Loudin knows just the leverage to use on his captive, and she is forced to choose between the two of them. Is her first love her true love? Or does Alex ultimately claim her heart? Unsure of everything around her, including her own identity, Thalli doesn’t know where to turn. She knows she needs the Designer, but he seems further away than ever. What she does know, though, is that if she doesn’t do something to stop Loudin, the fragile world aboveground will be lost once and for all.