‘Duch’ is the nickname of Kaing Guek Eav. In 2009 he was the first leader of the Khmer Rouge to be tried by an international war tribunal. Between 1975 and 1979, he was part of the horrific regime that had Cambodia in its grip, first as administrator of the M13 prison and later of the S21 camp, a ‘murder machine’ in which the remaining archives suggest that 12,380 people lost their lives and probably many more were ‘destroyed’. Rithy Panh has for years chronicled the Khmer Rouge and allows Duch to tell his own story frankly and unhindered, in a dialogue. But where Duch paints a picture of himself as only a cog in the machine, archive footage and eyewitness accounts provide a very clear picture of that hellish machine which led to the death of almost 2,000,000 Cambodians – about a quarter of the population. Panh lays bare the mechanisms of a system that left no space for humanity.