Han Hu, who had just returned from New Zealand, received a video call from Shen Junfeng, but the screen suddenly went black in the video and Shen Junfeng disappeared. Han Yan called the police and rushed to Shen Junfeng's home, but when the police broke open the door to the room, everyone was shocked... A series of exchange murders occurred, but there was no trace of the real murderer. Who was behind the scenes? What is the special meaning of the strange blood-lettered symbols? And who will die next?