Zhang Yifan, a renowned physician, transmigrates to the Dayu dynasty. He wakes to find a plague raging and the land strewn with the starving dead. In an effort to save lives, he accidentally answers the emperor's call for help. Using modern medicine, he brings the dying empress's fever down overnight, but is drawn into the palace's hidden currents as a result. Stranger still, he discovers that he is the legitimate crown prince, who was separated from the empress and raised among commoners for twenty-six years. The plague sweeping the realm is actually the result of poison spread through a conspiracy between a Northern Di cult and treacherous court officials. At this life-or-death moment, he awakens the "Plague Prevention System," which gives him unlimited access to modern medicines and medical equipment. As he treats the people with streptomycin and quarantine measures while investigating the source of the plague, he must choose between the struggle for imperial power and a physician's compassion: should he settle into life as crown prince, or use his medical skills to save the realm?
