There's a dangerous, sealed altar on the island of Cizierma that one must never touch. It's respectfully called The Forbidding One. There's also a girl named Aster. She is determined to become a guardian of this altar.

Aster must undertake a trial in order to prove her worth. The crew and the trial's proctor, Sutera, accompany Aster to the cave where the altar stands.

Now, this is no ordinary cave. It's said that strange things happen to those who enter but are not of strong heart. Do our heroes dare to step foot in such a place?