High Magic had been lost to Valdemar centuries ago when the last Herald-Mage gave his life to save the kingdom from destruction by dark sorceries. Yet now the realm is at risk again. And Elsperth, Herald and heir to the throne, must take up the challenge, abandoning her home to find a mentor who can awaken her untrained mage ablities.

Heading home from school, Karigan G'ladheon encounters a dying "Green Rider", one of the king's messengers, who begs her to complete his mission. She reluctantly agrees and finds herself caught in a world of dangerous magic and even more dangerous enemies.