In the conclusion to the series, three sisters will fight for the future of the island. The battle with Katharine has left the rebellion in tatters, and Jule's legion curse has left her mentally unfit to rule. Arsinoe searches for a cure at the same time she strives to stop the ravaging mist from harming more of the land. Katherine, meanwhile, rues her attack on the rebellion--necessary as it was--for the loss of her beloved Pietyr. With no one to rely on, Katharine begins hearing the whispers of dead queens, telling her not to trust Mirabella who presents a truce.