Prince Astathe last surviving member of a royal familymust fulfill a quest before he can claim the throne: find the legendary Key to the Kingdom. The next phase of the quest begins, as the competitors search for The Invisible Tower, an elusive location containing an important clue about the quest. A new competitor enters the ring: Fireheart, a man who is seemingly impervious to the flames of the Dragon Men. He welcomes Prince Asta and his protector Badd to his castle. There he shares with Asta his knowledge of a family secret he learned from Astas fatherthe late King of Landorjust before he died.