There is always another monster. After weeks of terror, Cass has stopped an immortal killer, made peace with the Fae, and is enjoying some well-deserved happiness with her Warden, Merich. But a betrayal from within her own family cuts that happiness short, and leaves them exposed to a new threat. This enemy is different than the others. Worse. Hungrier. And as winter descends, bringing a new kind of darkness, Cass is no longer simply defending her position as the Witch, but fighting for her sanity and life. If she wants to save her family, it’s a fight she has no choice but to win. But everything has a price. And the cost of victory might be too high.