Synopsis：In order to protect her clan, Murong Xiaoxiao is forced into a contractual marriage with the heir of the leading family. Shortly after the wedding, the Murong clan is brutally massacred. Determined to find the killer, she adopts the alias Mu Xiaoxiao and enters the Mercenary Center, becoming a top assassin. Six years later, Mu Xiaoxiao is accidentally embroiled in an assassination plot, and her son Mu Maomao is mistakenly kidnapped by members of the Black Night Group. With no other choice, Mu Xiaoxiao disguises herself as a man and infiltrates the Black Night Group as a driver, going undercover while staying close to its CEO, Xuan Yuanlie. Mysterious assassination attempts occur one after another against Xuan Yuanlie, yet the identity of the perpetrator remains unknown. Around the same time, Mu Xiaoxiao inadvertently reveals her true gender, arousing Xuan Yuanlie’s suspicion. After several rounds of probing, her secret is exposed, and the hidden past behind Xuan Yuanlie gradually comes to light.