Su Wantang, the concubine of the Su family, was forced by her aunt to replace her seriously ill sister into the palace as a concubine because she looked exactly like the late emperor Bai Yueguang and Lin Zhaoyi. After entering the palace, she not only had to deal with the serial schemes of the queen and concubines (such as framing the emperor's heir, poisoning and causing illness), but also faced the hot and cold mood of the emperor Xiao Jingheng - sometimes the emperor was gentle because she resembled Lin Zhaoyi, sometimes he was indifferent because she was not Lin Zhaoyi. The heroine gradually grows up in the palace battles, from being patient and seeking survival to taking the initiative to fight back. At the same time, she reveals the secret of Lin Zhaoyi's death (the queen was poisoned), and allows the emperor to let go of his obsession with being a substitute. She finally gets rid of the label of "stand-in" and becomes a real winner in the harem and the emperor's true lover.
