Late at night in Jianglin City, forensic doctor Qin Zhao stopped the lancet in his hand in front of the autopsy table - on the left shoulder blade of the fourth corpse, the same dark red crescent mark as the first three murder cases suddenly appeared. This tragedy, called the "Blood Moon Serial Murder Case" by the media, is tearing apart the tranquility of the city once every nine days.
Lu Zheng, the criminal police captain who was suspended for violent law enforcement, encountered a strange scene while tracking down a suspect: the rooftop was clearly empty in the surveillance video, but witnesses insisted that they saw a woman in costume jumping off a tall building. What made him even more horrified was that the sandalwood doll held in the deceased's palm was exactly the same as the relic of his father who died in the line of duty eight years ago.
When the criminal investigation genius and criminal psychology professor Xia Ying formed a special investigation team, they discovered that all the victims had been admitted to the municipal mental health center six months ago. As the hacker genius hacked into the deleted medical records, a yellowed file with "Nirvana Project" written on it linked the bloody totem to an illegal brain experiment thirty years ago. And the fluorescent blue pills left in the stomach of each corpse are piecing together the chilling truth.
At this moment, a blood moon rises in the skyline of the city, and a dark nursery rhyme suddenly circulates on the mysterious forum: "Seven layers of gauze are dyed with cinnabar, and the dolls are tied with crescent scars." When Lu Zheng discovered a wall full of photos of victims in the cellar of his childhood home, including Qin Zhao who was working overtime in the autopsy room. And the boss behind the scenes who calls himself the "Puppet Master" is using a voice changer to hum the lullaby that Lu Zheng's mother sang before she died in the live broadcast room...
