If you’ve had the pleasure (and I use that term very lightly) of seeing Joshua Oppenheimer’s astounding documentary The Act of Killing, then you know exactly what to expect with this, its equally stunning companion piece. The Look of Silence returns to Indonesia, the scene of a horrific genocide back in 1965, when over a million people were mercilessly butchered by the military dictatorship.

While the content is as distressing and powerful as its predecessor, what immediately sets The Look of Silence apart is its far more personal approach. The first film followed the perpetrators themselves as they re-enacted their crimes, making an already disturbing film quite surreal. Here though, we follow Adi, the brother of one of the victims, as he visits each one of the killers and confronts them about their involvement in the murder. Using the lure of a free eye test (he’s an optometrist) Adi starts to gently probe, and the resulting conversations are some of the most powerful moments of cinema I have ever seen.

The most remarkable thing about this movie, for me, is Adi. Considering the incredible amount of pain that discussing his brother’s death must cause him, as well as the very clear danger of confronting these dangerous men, he remains calm and collected throughout. His questions are perfectly worded, forcing his ‘interviewees’ to say more than they’d like, but those questions are delivered with such a serenity and humility that it’s impossible to get angry at him.

The murderers, in turn, vary from the downright heartless to the ones unable to vocalise the guilt so clearly etched on their face. The truth is in the silences, those moments where questions are unable to be answered and emotions are being held back. But equally amazing to see are the exchanges between Adi and his own family – his 100-odd-year-old parents getting on with life as the tragedy continues to hang over them; and Adi’s children, who are being taught at school that the genocide was a good thing. That juxtaposition of familial beauty and detached coldness is immensely powerful and breathtaking to watch.

The Look of Silence isn’t for the faint-hearted – acts of horrific torture and violence are discussed with a frankness that is at times unbelievable. It’s a film that you’ll think about long after you’ve watched it (I still am), and that’s in large part to the power of Oppenheimer’s filmmaking. I would put The Act of Killing up there as one of the best documentaries I have ever seen – The Look of Silence isn’t far behind on that list. A visceral, disturbing, emotional rollercoaster of a movie; cinema at its most human.