While exploring a mysterious cave, Guin and the others encounter a strange ball of light that renders Rinda unconscious. As they attempt to flee the orb they are attacked by a giant monster, but manage to reach the Garm's Head and flee the island. Meanwhile, the King of Mongaul is concerned about Amnelis' relationship with Naris, and plots to eliminate the Prince of Crystal. Vlad is also troubled by the escape of the twins, and dispatches Sid to locate them as quickly as possible.
島の洞窟でグインたちが遭遇したものは、内部に様々な色の光をたたえる巨大な塊のような物体であった。一方アムネリスがナリスと恋に落ちたことを知った大公ヴラドは、モンゴールの支配を危ぶみナリスを婚儀の後に殺害することを計画し、アムネリスの弟マリウスをケイロニアの皇女シルヴィアと婚約させようと画策して…。
