Twenty-five years ago, a nanny switched two babies to save her grandson, who had been conceived out of wedlock. The real young master was abandoned at an orphanage and grew up collecting scrap, while the impostor lived in luxury for 25 years. Twenty-five years later, Gu Tingshan encounters Lu Zheng, who has a clover-shaped birthmark on his shoulder, and immediately recognizes the mark as belonging to his biological son. Upon discovering the truth about his identity, the fake young master offers Lu Zheng 500,000 yuan to make him leave. But his biological father fiercely stands up for him: I gave him the key, and nobody has the right to take it back!