A nation called the Alliance rises out of the destruction of a massive asteroid impact. As disease decimates the world's survivors, the Alliance gains strength due to its mandatory organ donor system. This System forces the lower caste, "donors," to give up their organs to Alliance citizens-even to the point of death. Seventeen-year-old Joan, a gifted athlete, is the personal donor of the absolute elite of the elite, the pampered daughter of the ruling Governor. She has been ingrained by the harsh rules of the System her whole life, following the System willingly-yet she still harbors one last glimmer of inner freedom and the hope, that somehow, someway she can fulfill her romantic feelings for a young citizen named Duncan. But the rules of the System forbid any relationships of this kind. Whatever dreams Joan may have come to a crashing halt when she learns her next donation will be her last. The Governor's daughter wants the foremost cause of Joan's superior athleticism: her heart. No pleas or bargains can be made. Alone, Joan must flee and become one of the hunted, a small and as far as she knows completely dead minority. In a fight for her life, she must evade capture by a ruthless security force and find safety outside the nation's walls. This distant horizon is a complete unknown, spoken about only in whispers. The trials of facing these dangers not only awaken her long suppressed sense of self, but they provoke even greater challenges, for she is devastated to learn Duncan is one of those hunting her. For Joan, physical trials are second nature and if anyone can escape and survive outside the nation's walls, she can. But can she leave her family, her hope for love and her fellow donors behind?