The concubine Shen Zhiyi was regarded as an abandoned child by her family, and she was happy to marry the terminally ill "Xian Wang". On their wedding night, she discovered that the groom was not the rumored dying prince, but the cold and ruthless prince Xiao Yi who was supposed to be supervising the army at the border. An "identity oolong" related to the secrets of the royal family began - the prince exchanged identities with the dying emperor's younger brother in order to hide his identity from others and dodge open and secret arrows. In order to protect himself, Shen Zhiyi had to cooperate in acting. In the crisis-ridden palace (actually the East Palace Courtyard), he used aggressive methods to deal with difficulties from all sides, and used the wisdom of "pretending to be a pig and eating a tiger" to deal with all kinds of people. Xiao Yi only regarded her as a useful chess piece at first, but gradually he was attracted by her vivid vitality, unexpected agility and unyielding resilience. From utilization to preference, his possessiveness became increasingly strong. When Shen Zhiyi gradually discovers the truth and discovers that she may be involved in a deeper entanglement of royal blood, she must make a choice between preserving herself, protecting her true heart, and uncovering the mystery. In the end, the mystery of her identity was revealed, and she stood side by side with him, working hand in hand to break the situation in the turbulent court and harem, and write their own legend.