Gu Lingchuan, the young master of Qingcheng Mountain, returns to the Gu family disguised as a fool to see people's true nature. Using the bite mark he left behind in childhood, he reunites with his three elder sisters: Gu Mingzhao, Gu Shuyao, and Gu Xinghe. Gu Mingzhao has damaged tendons in both legs, Gu Shuyao has been poisoned by a mysterious toxin, and Gu Xinghe harbors a hidden danger. Conspiracies lie behind all their troubles. Gu Yichen, the fake young master who has occupied Gu Lingchuan's identity for twenty years, is actually a pawn planted by the Xuantian Sect. Kind and gentle on the surface but greedy and vicious within, he conspires with Qin Zheng, Gu Mingzhao's former fiancé, to repeatedly plot against the Gu siblings, seeking to seize the Gu Group and the token of Qingcheng Mountain.