A serial homicide occurred in Linghai City, and criminal police Ji Fan, captain Xiong Zhennan, forensic doctor Zhao Qingyan and others jointly launched an investigation. However, the case was complicated and confusing and could not be solved. As the investigation progressed, Ji Fan gradually realized that the murderer seemed to be nearby. The seemingly simple serial murder case involved an old case 27 years ago. The truth buried by time was slowly revealed. The murderer was His father Ji Tingshan and his elder brother Ji Ping had been with Ji Fan day and night, but Ji Ping had taken the task of revenge for Ji Fan for 27 years. Following the arrest of Ji Tingshan, Ji Ping was wounded and fled overseas.