In search of a better life, Cassia joins a widespread rebellion against Society, where she is tasked with finding a cure to the threat of survival and must choose between Xander and Ky. Cassia, Ky, and Xander return to the Society to save the one thing they have been denied for so long, the power to choose.

In search of a future that may not exist and faced with the decision of who to share it with, Cassia journeys to the Outer Provinces in pursuit of Ky--taken by the Society to his certain death--only to find that he has escaped, leaving a series of clues in his wake. Cassia's quest leads her to question much of what she holds dear, even as she finds glimmers of a different life across the border