When Mrs. Hsu comes knocking on the drunken Mr. Xu’s door one night, she ventures into the room when he doesn’t answer the door. Mr. Xu, is found dead in the room, next to him stands a dancing woman.

In fact, Xie Xiaowan - the celebrated courtesan that hung herself twenty years ago, is no stranger to the Xu family. But the sight of ten Xiaowans appearing in front of Mrs. Xu sends her into a frenzy. When the servants rush to her aid, they vanish before their very eyes.

Detective Shi Shen is sent to the scene, and finds Mr. Xu died from aconite poisoning. He is further baffled by the seemingly supernatural nature of the murder – when hair of the mythical Water Monkey is found at the site. He then embarks on a journey to the Hidden Town, in hopes that the practitioner Bai Qingluo, who can detect millions of odours, could help him unearth the truth.