It is one of history's greatest unknown crimes against humanity: More than a million people were killed after Indonesia's military coup in 1965.
The victims were accused of being communists, an umbrella that included not only members of the country's Communist Party but also all those who opposed General Suharto's new military regime.
This contrast between survivors threatened into silence, surrounded by the men who killed their loved ones, who are still in power and free to boast made me feel as though I'd wandered into Germany 40 years after the Holocaust only to find the Nazis still in power.
The killers were often members of paramilitary groups or death squads who carried out the executions with the approval of the military government and killed with impunity.
The perpetrators have stayed in power, living alongside the survivors and the victims' families who were threatened into silence. Fear and anti-communist rhetoric persist in Indonesia today.
For nearly 10 years, American filmmaker Joshua Oppenheimer researched and documented the atrocities.
He spoke to victims and their families as well as the perpetrators of the crimes, shedding light on Indonesia's dark past and today's impunity in his two films, The Look of Silence (2014) and The Act of Killing (2012).
His first film tells the story from the point of view of the killers - some of whom are celebrated as heroes in Indonesia today. The Look of Silence follows an optometrist, born two years after his brother was killed, as he meets those responsible for his brother's death.
"Neither film is a historical documentary about events 50 years ago. Both films are about a present-day regime of fear that subsists because everybody knows who the perpetrators are and knows what the perpetrators did," Oppenheimer tells Al Jazeera.
He says that the perpetrators in his films are performing - rather than re-enacting the past - "the present-day fantasies, lies, stories they tell themselves so they can live with what they've done".
Oppenheimer says that the films are fundamentally about impunity, but as he dug deeper, he realised it wasn't unique to Indonesia.
"What I was really finding there was an allegory for an impunity that defines so many of our societies."
The filmmaker explains how his films have helped to spark a movement for truth, justice and reconciliation in Indonesia.
"I think my two films have prompted a fundamental transformation in how Indonesia talks about its past. So The Act of Killing had kind of catalysed this shift in the media. Where the media before was either silent or even celebratory of the genocide, now it talks about the genocide as a crime against humanity. And more importantly, [the media] talks about the genocide, talks about the criminal regime that's been in power in some form or other ever since 1965."
Oscar-nominee Joshua Oppenheimer spoke to Al Jazeera while he was in Doha as one of five mentor filmmakers at this year's Doha Film Institute’s Qumra event. He spoke to us about his experiences documenting the Indonesian massacre of 1965 through the eyes of the victims and the perpetrators.
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