In an era of 24 hour 'breaking news', it's increasingly rare for a documentary to have significant impact, and even more so when that impact is aesthetic and ethical as well as political. Given this, American film-maker Joshua Oppenheimer is arguably the most remarkable and important new documentarian to have emerged so far this century. The Act of Killing and The Look of Silence, his astonishing, shocking and profound features revealing the suppressed history of the Indonesian Genocide of the mid 1960s, have won dozens of awards internationally. Many years in the making, they engage at the deepest levels with both perpetrators and survivors / relatives, using re-enactment, in-depth interview and acutely empathetic observation to create works of rare emotional, intellectual, even metaphysical power. In conversation with Gareth Evans, Film Curator at London's Whitechapel Gallery, the diretor will explain why and how the films have broken decades of silence internationally around crimes that remain entirely unpunished, as well as clearly indicting Western governments both in support of the atrocities themselves and the subsequent refusal to bring those responsible to justice.