Throughout the competition, Meg and Brek have traveled to three different worlds, changing their lives forever. But as Meg wakes behind the Black Door in the land of Periden, she finds the true creator of the game controlling everyone in his presence, and she's not sure who she can trust.

As her marriage to Carter approaches, Meg discovers powers within to help overcome the obstacles set before her. And the first one is sure to break her. Kill her best friend, collect his heart as the final object in the game, or become the hunted.

Searching for Brek, Meg discovers the Shadow Realm, a people with plans to rise up against the Eternals and take back their planet. There's a battle brewing bigger than anyone can imagine, and Meg must race to put an end to it before Carter puts an end to her.