Female detective Su Yan gets involved in the mystery of the "Xuanwu Tiger Talisman" in order to investigate the cause of her parents' death. She joins hands with Xie Yan, the crown prince of Dingbei who is pretending to be crazy, to solve an unsolved case that has lasted for ten years and uncover the old grudge of the late emperor's massacre of the Xuanwu Guards. They redeem themselves in both directions through the investigation and conspiracy, and finally become partners.
