Mujin, a palace maid, conceives the emperor’s child and hides her identity to survive. Her sister Mumian dies protecting her. Six years later, Mujin reunites with her son Xie Yu and Emperor Zechuan in the criminal slave yard. Mother-son instinct wins her the emperor’s trust. Noble Consort Rong and her father plot treason and infect the emperor with golden silkworm gu. Mujin trades her life to save him, and Prince Runan claims her as his daughter. The clever Xie Yu travels to Miao territory for the Nirvana Gu to save his parents. The emperor crushes the rebellion. The royal couple are cured, and Xie Yu ascends the throne to create a prosperous era.