To keep you is no benefit, to destroy you is no loss.'During the Khmer Rouge's four-year rule of terror, two million people, or one in every four, Cambodians, died. In describing one family's decades-long quest to learn their husband's and father's fate and the war crimes trial of Comrade Duch (pronounced 'Doyk'), who ran the notorious S-21 prison in Phnom Penh, where thousands were tortured prior to their execution, When the Clouds Fell from the Sky illuminates not only the tragedy of a nation, but also the fundamental limitations of international justice. In February 2012, the international war crimes court in Cambodia handed down a life sentence to the man known by his revolutionary moniker Comrade Duch. The court found the Khmer Rouge's former security chief responsible for the deaths of more than 12,000 people at S-21 prison.Duch's conviction was historic. He was the first Khmer Rouge member to be jailed for crimes committed during Pol Pot's catastrophic 1975-9 rule when two million people died from execution, starvation, illness and overwork as Cambodia underwent the most radical social transformation ever attempted. When the Khmer Rouge took power in 1975, the entire population was driven from the towns and cities into rural gulags, where they were put to work planting rice and constructing vast irrigation schemes Designed to outdo even Mao's Great Leap Forward, it was an unparalleled disaster.At the same time as the Khmer Rouge sought to refashion the country, they closed its borders, barred all communication with the outside world and turned back the clock to Year Zero. They outlawed religion, markets, money, education and even the concept of family as they pursued a revolution that would outstrip all others. In Orwellian fashion, everything and everyone belonged to Angkar, the anonymous leaders, and all loyalty was owed to them. The individual had no value beyond their utility as a working unit that could easily be replaced.It was not long before the revolution began to implode, driven to destruction by the incompetence and paranoia of Angkar. Yet instead of recognising their own failings, the leaders believed unseen enemies were undermining the revolution. They sought them everywhere, both inside and outside the movement. In their pursuit of purity they destroyed a nation. This was the closed nation to which Ouk Ket returned in 1977. Like hundreds of other returnees, he was utterly unaware of the terrors being wrought in the revolution's name. Hundreds of thousands of other Cambodians perished in nearly 200 institutions like S-21 that formed an inescapable web across the country. Most of the rest died of starvation, overwork and illness in the rural gulags. Cambodia remains defined by this cataclysmic period, and its effects are apparent today. To illustrate this era and its consequences, Robert Carmichael has woven together the stories of five people whose lives intersected to traumatic effect. Duch is one of those five, and the book tackles this complex man and his life through the prism of his trial.Through these five stories, through the author's own research, through interviews with leading academics, former Khmer Rouge and ordinary Cambodians, and by following Duch's trial, which Robert did for months, the book takes the experience of one forgotten man to tell the story of a nation. Since we cannot grasp the concept of millions of dead, he has used the murder of one to speak for the deaths of many. In so doing the book reaffirms the value of the individual, countering the Khmer Rouge's nihilistic maxim that: 'To keep you is no benefit, to destroy you is no loss.