Tang Bing'er (Jin Zixuan), a female college student of modern forensic medicine, accidentally comes to the body of Qin Xiyue, the evil concubine of Heng State. She uses the forensic knowledge she has learned to dispel the fog, repeatedly solve strange cases, and is reborn side by side with Prince Lingxuan (Li Junchen), and protects the stability of the people of Heng State.