Story :  The hit manga "Trace: Recollections of a Forensic Researcher," with a TV adaptation starring Ryo Nishikido, branches out in this dark and gritty spinoff. There is a man who brings the worst deaths possible to criminals the law cannot judge. His name is Hiroki Dan, from the MPD homicide division. The son of the ex-MPD commissioner-general, on the career track to success, has a secret side as a serial killer with over 100 criminal victims. Vigilante justice beyond the death penalty is doled out to criminals in this pitch-dark suspense.