The Harbingers descend into the Arcanium tower above the Aurorius Falls under the guidance of Felsis. In a corridor lined with mirrors, Torrin sees silent figures watching from within the glass. The tower reacts when Sabu disappears and Nixon returns, restoring the Harbingers' memories of two conflicting realities: one in which Nixon traveled with them and another in which he was erased. Every mirror shatters, and the broken glass forms a regenerating golem that drives the group down a vast spiral stairway. Bjorn shoves the creature over the edge, and Torrin manifests wings of glass to rescue him from the fall. The golem survives and attacks the inner sanctum below until Felsis destroys it with a fireball, leaving Bjorn trapped inside its molten remains until Torrin breaks him free.

Within the hidden Arcanium, the Harbingers meet Ariandre, a healer of metaphysical damage, and Horatio Vinvestler, the masked master who has been watching their journey. Horatio reveals that his visible body is a projection while his ancient physical form remains trapped inside a life-sustaining casket. He describes the tower as a creation of the Crystalline Order, identifies himself as a former member of the Siphon Order under Zyltrix, and claims that Whisper and Ernan are connected to the sealed Dios Ostium. Draxus Cale intends to open the passage through blood and might, while Horatio believes the Crystallic is the proper key. He warns that the Chain is marching toward Keph, the awakened dragons are gaining strength, and the Harbingers cannot protect every threatened community at once. He offers them refuge in the prosperous northeastern realm of the Wolf King if they surrender the Crystallic, but the group remains committed to restoring the Ithelion.

After the Harbingers warn Keph to prepare for a siege, Vyr asks Ariandre to help her contact the Crystalline Order. Ariandre projects Vyr into a vast liminal realm of floating mirrors, where the order condemns the Harbingers for remembering the mysterious green eyes and demands that those memories be erased. When Vyr tries to leave, the silk cord connecting her to the Arcanium refuses to break. Another power tears her away from the order and carries her through a vision of an impossible bridge across the sea, a gatehouse, fields of thorns, and a floating city bound in chains. At the edge of a star-filled abyss, Vyr confronts Cellus, an immense crystalline dragon whose eyes contain galaxies. Cellus tells Vyr that she has risked much, but her story is not finished and the dream cannot end yet.