Watch Sadisflix. After a long, arduous hunt, Derek Ho, Singapore's first serial killer has been captured, tried and sentenced to death. As he awaits his fate in prison, a team of top psychologists is assigned to interview him. They must find out if he has any information on a list of women reported missing during the period of his killing spree. It takes a young, ambitious member of that team, Dr Winnie Low, to break through to the stubbornly reticent Derek. Winnie embarks on a journey to solve the mystery, unlocking a secret deep within Derek's past... one that gives her an insight into how he went from an ordinary man to extraordinary killer.