Sin of Purification

On a rainy night, a female body was found in a locked bathroom. The water in the bathtub was a strange light blue, and the mysterious symbol "♰" was engraved on the mirror. Criminal investigation captain Chen Mo discovered during his investigation that this was actually related to a mass death case in a mental hospital twenty years ago - and his father was the veteran detective who was in charge of the case but died suddenly "accidentally". When the second deceased person appears, also drowned in the bathtub and engraved with the same symbol, Chen Mo is forced to face family secrets: his father may have participated in illegal drug experiments, and the murderer is following a certain "purification ritual" to hunt down the descendants of those involved one by one. What's even more frightening is that the real murderer seems to be related to the "Judge", the serial killer who committed suicide three years ago, and may even be an experiment survivor who should have died. As the investigation deepened, Chen Mo discovered that his blood was the only antibody that could resist the mind-control drug "TS-117." What the murderer wants is not only revenge, but also a city-wide "seawater purification" to complete the crazy experiment that was interrupted twenty years ago...