When registered clinical psychologist CHUNG TAI-YIN is driving on the highway, he recalls the past and cannot help tearing up. For research, TAI-YIN interviewed a murderer LO KIN-KEUNG a year ago. KIN-KEUNG is extremely sensitive. TAI-YIN adopts every possible way to try to trigger his memory of the murder, but to no avail. Upon TAI-YIN’s return home, his girlfriend, TSANG SAU-YEE who is also a psychologist, asks him about his opinion after the interview. TAI-YIN does not believe that KIN-KEUNG would ever hurt anyone, so he is determined to solve the mystery. There is a virus in the computers of the company that TUNG YAT works for, so his boss immediately tells him to fix the problem. However, TUNG YAT’s response makes his boss so angry that he yells at him. TUNG YAT’s sister, TUNG YUET, is a social worker.… ...