Retired detective Lu Zhengting and forensic doctor Song Qingtang met because of a corpse tattooed with strange symbols. The two teamed up to investigate, but found that each seemingly independent murder case pointed to the Red Lake corpse case twenty years ago-that was the mystery of the death of Song Qingtang's father. Clues to the disappearance of Lu Zhengting's wife also surfaced. Reporter Zhuo Ya, detachment leader Han Yue, and psychologist Jiang Muyun are involved in the conflict from their own standpoints. In the maze of lies and truth, logic is the only knife that can cut through the darkness.
