Forensic doctor Chen Xiaoli was transferred to the serious crime team of Gaojiang City Police Department because of her persistence in the truth, and she partnered with Guo Lin, a genius in solving crimes who was decentralized for violating discipline. Starting from a drowning case of an Internet celebrity that was disguised as suicide, the two relied on Chen Xiaoli's microscopic evidence analysis ability and Guo Lin's macroscopic logical reasoning to gradually tear open the cracks in the calm surface of Goryeo City. They discovered that the strange cases in front of them seemed to be puzzle pieces leading to the same dark core, and all of them seemed to be closely related to the unsolved case that changed Guo Lin's fate seven years ago. When trust is tested and when the truth challenges justice, this "flawed partner" must support each other in the fog and uncover a chain of sin that spans many years.
