Yun Qiyue traveled through time and became the concubine Luo Ningzhi who was poisoned. She pretended to have amnesia to protect herself, and used her pharmacological knowledge to kill her poisoned stepmother. However, she was treated as an abandoned son by her family and given to Prime Minister Pei Xuanming as a concubine. It is rumored that Pei Xuanming was ruthless and went crazy because of the untimely death of his late wife (who had a similar appearance to the heroine). She was forced to become a substitute, but found out that Pei Xuanming had known about her identity and kept her by his side to find out the evidence of rebellion between the merchant family and the prince.
The two tested each other: she used Pei Xuanming's power to take revenge on the family, and he used her wisdom to organize the court. She made perfume and opened a medicine hall, and used her business skills to help him relieve disasters; he taught her power and blocked assassinations for her. When her heart moved, she heard that "Bai Yueguang" was not dead, and that she was just a chess piece. In order to protect her from being poisoned and dying, Pei Xuanming confessed that he had been attracted to her for a long time. The substitute lied to force her to grow up and protect herself. In the end, she saved him with modern medical skills and worked together to uncover the conspiracy. He gave up his official position and took her away, but she chose to stay and rule the world with him.
