A progression fantasy. After learning the family secret, Evelyn's beautiful twin vanishes, leaving only a used, magical tome as a clue to her fate. Not knowing which faction assisted with Teresa's disappearance, three generations of the Aynchant family must leave the shires of England to find or save her. They travel with the tome, to a medieval world controlled by tyrannical magicians. Katerva must learn and use magic in a race against time to reclaim the Aynchant birthright.