Xiangrong, an orphan girl from the Hua family, accidentally met Su Yan, the princess of the subjugated country, and began a twenty-year friendship. One is the most undercover agent in the empire, the Empress Dowager, and the other is Concubine Chen who is the most favored harem queen. Facing the mystery of their life experience, the changes in the palace, and the hatred of their family and country, where will they go?