In the deeply divided world of Caldera, nothing is as it seems. Taken captive by a faceless enemy, Sephone Winter fights to reclaim her soul as her gift spirals out of control and the deadly poison coursing through her veins begins to exact its terrible vengeance. Meanwhile, Dorian and Cass are forced into an uneasy alliance in order to find the woman they both love . . . a woman who has all but vanished from the face of the earth, along with the Reliquary. Finding her becomes impossible as the identity of their greatest adversary continues to elude them. When Caldera's past catches up with the trio's future, Sephone, Dorian, and Cass are forced to make decisions that threaten everything and everyone they care about. Each of them is offered a chance to sacrifice their own happiness for the sake of the other-but will they take it? And what will it cost them in the end?