Shen Mingzhu, the daughter of a businessman, was betrothed by her father to the son of a notorious warlord in the city. On the wedding day, she found an opportunity to exchange identities with her twin sister who was working as a concubine in the Marshal's Mansion, trying to escape from the marriage. However, as soon as she entered the Marshal's Mansion, she found that the Marshal's Mansion had turned into a prison - the Marshal had been assassinated, and the murderer was inside the mansion. She, the "fake concubine", must find the real culprit among a group of jackals, tigers and leopards and clear her suspicions. At the same time, she accidentally discovered that she and her sister were not born twins, but were created by her mother to confuse the royal bloodline. Their mother is the real "princess". This serial killing was set up by the elders of the royal family in order to find the "Jade Seal" that symbolizes imperial power.
