Police officer Wu Jie is about to take her own life when the body of a young Thai woman washes ashore. A cut-off finger and a missing heart only confirm that what looked like a tragic accident is a murder, and evidently a gruesome one. As the number of missing women climbs, Wu Jie braces herself, pushes her demons aside and together with her rookie colleague dives into the pattern of grisly clues and unreliable scraps of evidence. The awareness that the killer might strike again gives the investigation the tension of a torturous, incessant drip of water.