At the beginning of the episode, Frieren and her companions discuss their strategy for battling the replicas, which turn out to lack minds, making their initial approach difficult. From Lawine, the group learns that the copies are controlled by a mythical monster named Spiegel, located in the treasure vault behind a sealed door. The spell sealing the door can only be broken by defeating the caster, prompting the group to devise a strategy to overcome this obstacle.

Frieren reveals a personal weakness: she briefly stops sensing mana when casting spells—a flaw that embarrasses her. The group decides to exploit this weakness in Frieren’s replica and plans an attack that leverages Fern’s ability to remain undetected to cast the quick spell Zoltraak.

The scene then shifts to a flashback in which Serie delivers a message from Frieren’s deceased master, Flamme. Flamme’s will reveals that the emperor has approved nationwide magic research, marking a significant step toward widespread magical use in human society. Serie disapproves of this development, valuing the exclusivity of magic.

The climax of the episode is a meticulously executed battle in which Frieren and her apprentice Fern use their understanding of each other’s strengths and weaknesses to defeat the replica. The fight not only showcases their combat skills but also the strategic depth of their planning. The victory underscores the theme of passing the torch, as Fern, a human mage, plays a decisive role in defeating the replica, symbolizing the dawn of the "Age of Humans" in a world previously dominated by elves and other magical beings.