À la fin des années 70, le régime khmer rouge a tué environ deux millions de personnes au Cambodge soupçonnées d'être des «ennemis internes». Trente ans plus tard, motivé par la perte de sa famille pendant cette période, Thet Sambath se lance dans une quête pour découvrir les vrais faits sur les responsables du génocide cambodgien.

The Khmer Rouge slaughtered nearly two million people in the late 1970s. Yet the Killing Fields of Cambodia remain unexplained. Until now. Enter Thet Sambath, an unassuming, yet cunning, investigative journalist who spends a decade of his life gaining the trust of the men and women who perpetrated the massacres. From the foot soldiers who slit throats to Pol Pot's right-hand man, the notorious Brother Number Two, Sambath records shocking testimony never before seen or heard. Having neglected his own family for years, Sambath's work comes at a price. But his is a personal mission. He lost his parents and his siblings in the Killing Fields. Amidst his journey to discover why his family died, we come to understand for the first time the real story of Cambodia's tragedy.