The continent of Gatheon burns. From the ruins march the Children of Matrixia, unleashing monstrous hordes that spread like a plague through every duchy. Xelea's ordeal has left her fractured, the wounds on her body mirrored by the shadows taking root within her soul. Rem, newly awakened to powers he barely understands, is beginning to grasp the terrible role fate has chosen for him. With annihilation closing in, the coven must rise above heartbreak, fear, and doubt-because if they falter now, their world will fall. Thus concludes the Book of the Thirteenth.