Chasing down an uncertain future, Cassia makes her way to the Outer Provinces in pursuit of Ky-taken by the Society to his certain death-only to find that he has escaped into the majestic, but treacherous, canyons. On this wild frontier are glimmers of a different life and the enthralling promise of rebellion. But even as Cassia sacrifices everything to reunite with Ky, ingenious surprises from Xander may change the game once again.

All her life, Cassia has never had a choice. The Society dictates everything: when and how to play, where to work, where to live, what to eat and wear, when to die, and most importantly to Cassia as she turns 17, whom to marry. When she is Matched with her best friend Xander, things couldn't be more perfect. But why did her neighbor Ky's face show up on her match disk as well?