Rudeus receives a letter from Paul. The letter explains that Norn and Aisha, Rudeus's younger sisters, have been sent to join Rudeus. Meanwhile Nanahoshi continues her research into summoning magic for a way to return to her original world.

Norn shuts herself in her dorm room and refuses to attend classes. Haunted by the specter of his past life, Rudeus sets out to solve his sister's problems, only to discover that he is the cause.

Rudeus and Elinalise reach Rapan and soon reunite with Paul, only to learn that a deadly labyrinth has claimed both Zenith and Roxy. The fruits of Rudeus's studies offer a last, faint hope to reach his mother and his mentor in time.

With Roxy's rescue, the search for Zenith resumes in earnest. Rudeus reconnects with his mentor amid the perils of the labyrinth. But why does she seem a little more awkward around him than before?

The rescue party reaches the heart of the Teleporter Labyrinth and confronts its guardian. But when the monster shrugs off Rudeus's magic, they realize they may have bitten off more than they can chew.

Roxy makes a desperate move to pull Rudeus out of his depression. As the group journeys home, both of them must face their feelings and negotiate the consequences.