Maomao visits Shishui, a moth caretaker in the rear palace, to request her assistance in a plan involving nocturnal moths. Their collaboration culminates in a splendid banquet held in honor of foreign envoys, taking place at a historic site—the very location where, decades ago, an envoy witnessed a legendary performance. During the event, Maomao discreetly observes the envoys—particularly the sisters Ayla and Aylin—and takes note of Ayla's pointed remark about the absent younger brother of the emperor.

Meanwhile, Jinshi prepares to appear as the "Moon Spirit"—a ceremonial role linked to the Western moon goddess Diana. His ethereal dance captivates the envoys, but afterward, Ayla and Aylin confront Maomao. She deflects their inquiries by invoking Diana’s name, subtly undermining their plans. After the banquet, Maomao explains to Gaoshun how Shishui’s moths created an illusion to unsettle the envoys.

The next day, Xiaolan reveals that she has enrolled in a new school, while Maomao reflects on the perfume incident—a suspected ploy by the envoys to infiltrate the ranks of the concubines. Flashbacks reveal Maomao and Jinshi’s theory: the envoys smuggled perfume to manipulate the court, but their humiliation at the banquet thwarted the plan.

Subplots intertwine as Ailan falls ill and is taken to the clinic, where a strict staff member kicks Maomao out. Later, Jinshi and Gaoshun warn Maomao not to draw excessive attention with her medical activities. The episode ends with Ailan discovering a mysterious paper containing an unknown substance, while the clinic staff interrogates her about Maomao’s actions.