Prince Walter can't earn his knighthood without proving himself on a quest. Unfortunately for him, all seems peaceful in the kingdom of Arualia ever since the White Cougar was defeated. Aaron can't decide whether he really wants to be a knight at all. Is there something else he wants more?

But when a mysterious librarian with an alarming revelation about Aaron's sword points Walter, his sisters, and Aaron toward the disappearance of a race of creatures called barbegazi, the children are caught up in an ancient conflict. On an unfamiliar mountainside, they find themselves at the whims and mercies of a fire-wielding witch. They must enter a desperate search to the heart of the mountain to find the secret of Aaron's sword before the witch takes the sword's power for herself – and an entire race pays the ultimate price.