The fourth episode. The related story is: an honest-looking security guard has an irresistible animal desire in his body. He has done something unexpected to the human body and needs a mosaic to see it. Content abstract: Qin Ming, the god of forensic medicine in Longpan Police Department, became famous with superb professional skills in an overseas case. He should have gone further and further on the road of the cold male god, but subtle changes have taken place because of the appearance of the new forensic assistant Chen Shiyu. Qin Tao, an inseparable "golden partner", is even more powerful in his work because of female forensic's participation. The expedition composed of three people experienced bizarre and tragic scenes again and again, and avenged the complex case in Longfan City through the clues on the body. However, the growth of evil is hard to stop, and a ghostly killer suddenly rises in the city. This person's whereabouts are difficult to distinguish, leaving no traces of committing crimes, and even arrogantly leaving a bloody signature at the scene of the murder-the street sweeper, the nightmare of Longpan citizens began.