A top assassin transmigrates into the body of a bullied foolish ugly girl, takes the initiative to call off the engagement and punishes her malicious relatives. With her excellent medical skills and talent, she saves the emperor at a palace banquet and is granted the title of county lord. She joins forces with her former fiancé to quell the rebellion, eventually becomes empress to rule a prosperous era together, and opens a wide range of medical clinics to help the people.