When her grandmother falls ill, Lucia Dol'Auclair has to leave her sheltered life and travel to Eirini Academy of Mystics to compete in the Triune. In three events, she will compete against vampires and werewolves to take her grandmother's place as the guardian vessel of a destructive celestial of magic and prove her worth as heir to her royal coven. But, her heart is pulled in two directions when she falls for her rival, Adelaide, a troublesome vampire who doesn't play by the rules. Lucia is forced to choose between the traditions that hold her coven together and the passion that could tear apart her world.