Chen Fei (Sun Honglei), the captain of the criminal police, has been a police officer for many years. This time, the arrest of the serious criminal Du Gang caused the general manager of the steel plant, Li Weicheng (Li Qiang), who cooperated in the arrest, to be injured. In addition, his old partner Hu Jianguo was assassinated, which made Chen Fei fall into self-blame and depression. Fearing that Chen Fei would lose control of his emotions due to the loss of his friend, the director handed the murder of Hu Jianguo to the new head of the serious case team. Chen Fei was dissatisfied with the director's decision. He decided to investigate the case alone and in the tiger's den to comfort the souls of his comrades in heaven. Various signs cast suspicious eyes on Li Weicheng of the steel plant. Facing Chen Fei who was pressing step by step, Li Weicheng took a different approach and bribed the doctor Ji Xuefei (Dong Xiaoyan) to falsely accuse Chen Fei of suffering from mental illness. Chen Fei relied on Su Zhaolong (Wang Kuirong) to secretly support and force Li Weicheng to confess his crimes, and turned against him and confessed the manipulator behind the scenes-He Jingyi (Wang Fuli), chairman of the steel plant...