During the investigation, several police officers investigated the story of the real person behind the murder ten years ago. The tragic death of his father many years ago made Pei Zhenyu resolutely return to the place where his father worked after graduating with a master's degree, just to find out the truth of that year. All clues pointed to the father of the person he loved. However, are those really the facts of the past? When the fog is revealed and the damage has been done, how can he save his lover?