A case of corpse abandonment at the port that had been settled for three years suddenly resurfaced - the same technique, the same details, but the deceased was the younger brother of the victim three years ago. After receiving the case, criminal investigation captain Shen Yu had nightmares again and again. He always saw the blurry face of the next deceased in his dreams. And Chen Xu, a forensic consultant who has just been transferred back to the city bureau, has an unknown secret: as long as he touches objects related to death, he can "recall" the memory of the deceased's last few seconds before his death.
Two people with complementary abilities but wary of each other were put on the same front. During the investigation, they accidentally came into contact with the "mirror world" on the dark side of the city - an inner world composed of unresolved resentments. Here, the memories of people who died unjustly will replay themselves repeatedly, and a mysterious existence codenamed "Dark Song" seems to have been waiting for their arrival.
As the third and fourth "perfect suicides" occurred one after another, Chen Xu found that his abilities were being "marked" invisibly, and each time he looked back was consuming his life; and Jiang Yu's nightmare began to show more bizarre scenes - Chen Xu lying on the autopsy table, becoming the next corpse.
Behind the case is an ancient rule in the mirror world: resentment must be carried by someone. If no one takes the initiative to become a container, someone will passively become a sacrifice. Song Ci, the undertaker of the funeral parlor, is the current "vessel". His body has been eroded by countless resentments, and another "he" in the dark is trying to break the rules and use the lives of living people to fill the cracks in the mirror world.
Chen Xu and Shen Yu must uncover the truth about the disaster twenty years ago before the other party is completely "marked". And when the past and the future meet in the mirror world, they discover that the encounter between the two people was no accident from the beginning.
Intention: I can see your death, can you catch my fall?