I arrived in Cambodia for the first time in 2009, and made three more visits there over the next year or so, working with my colleagues on a study of a programme run by the NGO Helen Keller International, which was designed to improve the nutritional status of poor rural households through agriculture, animal husbandry and education. I did not know what to expect: my stored images of the place were shaped by hazy childhood memories of 1970s-era news reports and a rather clearer recollection of the film ‘The Killing Fields’. I’d read about the monstrosities perpetrated by Pol Pot and the Khmer Rouge, but had little sense of what had taken place in the thirty-odd years since that period ended. Whenever I met someone for the first time, I found myself estimating their age, in order to situate them in terms of that awful history. One Saturday, I took a tuk-tuk to the killing fields site, outside Phnom Penh. It was an innocuous looking place: without the signposts and the skull-filled stupa, you would hardly have known what horrors had taken place there. More nightmarish still was the infamous S-21 detention centre (Tuol Sleng), which was housed in a converted school in central Phnom Penh. The idea of turning a building designed for teaching children into a torture and interrogation centre represents an especially grotesque inversion: from the giving of knowledge to its agonizing extraction. All this was difficult to reconcile with the otherworldly beauty of the vast Angkor Wat complex, which I managed to visit on my penultimate trip.