In order to investigate the truth behind the mysterious death of her twin sister, Shen Xiyin, a former genius in the medical field and a top forensic doctor, entered the Bo family of the lifeblood conglomerate incognito and became a private nanny. The Bo family mansion is hierarchical, just like a modern palace, with several houses competing for power. It is called a wealthy family, but it is actually a colosseum. The "eldest young master" Shen Xiyin serves, Bo Yehan, is rumored to be terminally ill and has a violent personality.
Shen Xiyin used superb medical skills and meticulous forensic logic to repeatedly solve strange cases at wealthy dinner parties and group intrigues, and sent to prison one by one those "royal relatives" who used chronic poisons, fake accidents, psychological suggestion and other means to kill people. She is both a submissive nanny and a knife-wielder in the dark. As the investigation deepened, she discovered that Bo Yehan's "illness" was also a carefully designed murder. The two went from testing each other to joining forces to break the situation, and finally overthrew this rich and cannibal family.
