Three schoolgirl murders. Two killers hiding in plain sight. Six video tapes that horrify the world and lead to one of the most controversial murder trials in modern history: one that left a nation shamed, victims denied justice, and a serial killer roaming free in Canada today. Over the course four parts, follows the extraordinary twists and turns of the case and trial of glamour couple Paul Bernardo and Karla Homolka, the "demonic duo of dark kink", who quickly became the most notorious killers in Canadian history.