Years ago, sorceress Aetria's untamed power caused a disaster on the battlefield. Temporarily banished for retraining, she has returned to the army to redeem herself as head of a company of novice mages. Under the command of her old nemesis, Adept Pleates, she struggles with her past disgrace and her still-uncertain control of her magical energy. When Pleates assigns her to escort the army's commanding general and his aide on a covert mission, Aetria sees a chance to prove her worth. To her surprise, she unearths a traitor's plot and previously unknown secrets of the source of magic. At the same time, she discovers long-lost kin and encounters an unsuspected ally in the depths of her own mind.