A bizarre secret room murder broke the peace of the city. Criminal investigation captain Gu Niansheng was ordered to join forces with criminal psychology professor Shen Yibai to launch an investigation. As the case progresses, dusty old cases emerge, and a criminal gang hidden in the darkness is gradually revealed. While Gu Niansheng is pursuing the truth, he not only has to face brutal criminals, but also deal with pressure and threats from within. She must uncover the truth in the fog and expose the ugliness of human nature in order to find the final answer and complete her own redemption.
