On a rainy night in late autumn, a strange alarm call came into the city bureau. There was no human voice in the receiver, only repeated tapping sounds.
In Room 402 of Huimin Community, the doors and windows were locked from the inside. A female corpse was sitting quietly on a wooden chair in the living room, as if she was asleep.
Criminal investigation captain Jiang Yi led the team to the scene. He thought it was just an ordinary secret room murder case, but he found a hollow ring mark next to the phone in the entrance.
This symbol is an unsolved case that has been haunting him for three years.
Forensic doctor Wen Yan is good at reading the secrets of the deceased from the subtle traces on the body that he had no time to tell. The two teamed up to clear away the layers of fog and discovered that the victim had been secretly spied on before he was killed.
The murderer can always enter and leave a sealed room without leaving any trace, lay traps in advance, and even take the initiative to leave clues to lure the police into the situation.
A series of cases broke out one after another, and hollow rings appeared repeatedly at the scene.
The murderer is not just asking for life, he is judging and playing games.
As the investigation deepened, Jiang Yi was shocked to realize that there was an invisible link between all the victims. The truth of the unsolved case three years ago was far more cruel than he imagined.
The peepers in the shadows are still watching.
The next ringback is about to ring.
