Jinshi reflects on his familial connection to the emperor, his brother, while practicing his swordsmanship. Later, he and Gaoshun encounter Maomao, who is listening to a teacher speaking about the legendary Wang Mu—mother of the first emperor—and the "Shrine of Selection," a place that traditionally legitimizes the ruler. The teacher explains that the shrine has been unused for decades after a plague killed the previous emperor's older brothers and mentions Luomen's past interest in it.

The emperor invites Maomao, Jinshi, and the teacher to explore the shrine. Inside the labyrinthine interior, they repeatedly choose doors of different colors until they come across a cryptic clue that Maomao cannot decipher. The teacher suspects Luomen might have answers. During a subsequent visit to the shrine, Maomao realizes that the door colors suggest possible color blindness in past emperors, which would explain the selection of the "correct" paths.

Through Maomao's analytical choice of divergent doors, the group reaches a balcony identified as the historical site of imperial coronations. The teacher confirms their conclusion and warns of the shrine's political implications. The episode ends with the group's return, as Maomao's sharp deduction unravels the shrine's mysteries.