The heroine Xia Zhi is the posthumous child of a serial killer more than 20 years ago and was adopted by the police who arrested her father. She has shown special intuition about the psychology of criminals since she was a child. When she grew up, she became a criminal police officer who was proficient in trace examination and criminal psychological profiling, and joined the Special Crime Research Department of the Qingzhou City Branch. In the process of exploring the original motive of his father's murder and studying whether he also has the potential to commit perverted murder, he and his companions solve bizarre and cruel cases one after another.