Princess Lin Shuyun, after being designated as the heir to the Dark Emperor, studied medicine among the common people since childhood to avoid danger. Concealing her identity, she married Lu Zixuan, a court official. To help her husband get promoted, she used the blood from her own heart as a key ingredient to treat the seriously ill Empress Dowager. Unexpectedly, Lu Zixuan had an affair with the Eighth Princess and even gave her a divorce document, casting her aside.