A documentary about the aftermath of the 1960s mass killings in Indonesia by Suharto's coup-installed military regime and death squads, The Act of Killing spirals into horrifying surrealism from a seemingly simple starting point: in this case, interviewing some of the paramilitary leaders and self-described "gangsters" employed to eradicate anyone deemed a "communist"-- in practice almost anyone not loyal to the new regime. The surprise is that these men are eager to tell their tales, often indulging in graphic detail to describe, for example, the best means of murdering captives without spilling much blood (with a wire around the neck). They even enjoy reenacting their state-sanctioned murders on camera, at director Joshua Oppenheimer's invitation, adopting the lurid styles of the Hollywood crime films that influenced them back in the day. We see the rotund, disheveled Herman Koto and the slender, debonair Anwar Congo-- the latter responsible for more than 1,000 murders, many carried out with that wire-strangling technique-- searching neighborhoods they once attacked for locals to play parts in a reenactment. What follows is ugly, even mad: Surrounded by a throng of onlookers, a proud and enthusiastic Herman shows the crowd how to panic. It's impossible to forget that some of these people might have suffered real crimes at Herman and Anwar's hands. More terrifying than any horror film, and more intellectually adventurous than just about any 2013 release so far, The Act of Killing is a major achievement, a work about genocide that rightly earns its place alongside Shoah as a supreme testament to the cinema's capacity for inquiry, confrontation, and remembrance. To call it a masterpiece is at once warranted and yet somehow limiting, the term somehow too narrow for what the first-time filmmaker has achieved.