The 23rd episode of Frieren: Beyond Journey's End, titled "The Challenge of the King's Tomb," revolves around the second trial of the mage examination. Sense, a first-class mage, explains to the eighteen examinees that their task is to reach the deepest level of the dungeon in the King's Tomb. She gives them a bottle containing a rescue golem that can safely bring them back to the surface, but failing to use it means failing the exam.

The candidates form various groups to tackle the challenge. While some prefer to work alone, others, like Frieren and Fern, team up. Sense decides to accompany Frieren and Fern but promises not to interfere with their work. The episode highlights Frieren's experience and knowledge in dungeon exploration, contrasting it with the varying skills and attitudes of the other participants.

As they progress, Frieren reminisces about her past dungeon adventures with her old comrades and reflects on her approach to exploration. The episode showcases her unique way of handling challenges, such as her calm reaction when surprised by a mimic and her preference to avoid magic that alters her appearance.

Meanwhile, other groups face their own struggles. Despite impressive teamwork and abilities, Denken's team suffers a setback when Lange is forced to use the rescue golem to escape a dangerous situation.

This episode also delves deeper into Fern's character, exploring her motivations and the source of her abilities.

The dungeon's challenges intensify as the groups encounter increasingly difficult obstacles, including clay replicas of themselves that push their skills to the limit.