Between 1975 and 1979 the seemingly peaceful nation of Cambodia succumbed to one of the most bloodthirsty revolutions in modern history. Nearly two million people were killed. As head of the Khmer Rouge's secret police, Comrade Duch was responsible for the murder of more than 20,000 of them. Twenty years later, not one member of the Khmer Rouge had been held accountable for what had happened, and Comrade Duch had disappeared. Photographer Nic Dunlop became obsessed with the idea of finding...