A still from "The Look of Silence," a film by Joshua Oppenheimer. (Drafthouse Films and Participant Media)

Bald and muscular, dressed in a black T-shirt, black pants and black shoes, Joshua Oppenheimer emerges from the darkness of a movie theater to stand again before an audience and talk about Indonesian genocide. He is urgent yet soft-spoken and striking in appearance, yet nothing too unusual for the East Village. He could be a monk or a heavy-metal guitarist — callings with which he shares an intensity and a sense of purpose — rather than the documentary filmmaker and MacArthur Fellow whose 2012 “The Act of Killing” was as radical a challenge to nonfiction form as it was to a system responsible for the deaths of 1 million people.

Oppenheimer, 40, describes that Academy Award-nominated film not as documentary but “a delirium.” He persuaded now-elderly henchmen who participated in the 1965 genocide — which was officially sanctioned as a purge of Communist agitators and their sympathizers — to reenact the killings as a way to make them confront those actions and accept their guilt in an atrocity. The ploy made for grotesque revelations, provocative in ways that won fans in eventual executive producers Werner Herzog and Errol Morris, for instance, but that also drew criticism for taking bold artistic license with such grave subject matter.

That the filmmaker fears for his life should he ever again set foot in Indonesia speaks to the work’s effectiveness. But there was more to come. Oppenheimer’s new film, “The Look of Silence,” which will open July 31 in Washington, is the companion piece in the landmark project, more than a decade in the making. The film shifts perspective from the perpetrators to the victims and the story of a family that has suffered profoundly in the long aftermath of the genocide.

“What does 50 years of living in fear do to a human being?” Oppenheimer asked an opening-night crowd in New York. The question was rhetorical but brought the director around to an oft-cited quotation, from William Faulkner: “The past is never dead. It’s not even past.”

Joshua Oppenheimer, pictured in 2013. (Marvin Joseph/The Washington Post)

That’s the case for Adi Rukun, the film’s protagonist, a middle-aged optometrist who was born after the genocide and never knew his brother Ramli, whose death has scarred the lives of his parents: his frail 100-year-old father, who has lost most of his sight and hearing, and his mother, who is the old man’s caretaker and also the chief mourner for Ramli. Rukun, who is raising his own children, has collaborated with Oppenheimer since 2004, when he began meeting and filming participants in the genocide.

As the filmmaker discovered as he met dozens of perpetrators living freely with no repercussions, Indonesia was something like Germany after World War II, but with the Third Reich still in power. “ ‘What if Nazis had won?’ may not be the exception to the rule, it may be the rule itself,” he said, speaking in an earlier conversation. “I knew I’d make a second film about what it’s like for survivors to have to live in such a regime.”

When Oppenheimer returned to Indonesia in 2012, he knew the clock was running. Once “The Act of Killing” was released, it could endanger him. The window was briefly open to make “The Look of Silence.” Rukun, who becomes the film’s persistent, if gentle, crusader for truth and justice, insisted that he be given a risky opportunity. “He said, ‘I need to confront the men who killed my brother,’ ” Oppenheimer recalled. Step by step, that’s what happens.

The risks were calculated. Each shoot was conducted with two cars waiting outside. Preparations were made to whisk Rukun’s family to a safe location if the need arose. Oppenheimer banked on the perception of his close association with paramilitary leaders and cabinet ministers who played a role in the yet-unseen “The Act of Killing.” And in an incidental stroke of luck that also provides a symbolic image for the film, Rukun’s profession as a door-to-door vision specialist meant that all the interviews included an eye exam.

“He’s talking to people who are willfully blind to the moral meaning of what they’re saying,” Oppenheimer said. In an early scene that is nearly incomprehensible, an operative in the genocide discusses in gruesome detail the necessity for the killers to drink the blood of their victims — or else risk insanity. Rukun replaces a lens in his optometric rig and asks, “Is this more clear?” And, indeed, as the subjects gradually become aware of what Rukun is after, they become angry and threatening. But the point has been made. “You ask deeper questions than Joshua,” one such subject tells Rukun, and then invites him to leave.

“The eye test was conceived to make it safer,” Oppenheimer said. “When you’re having your eyes tested, you’re disarmed. And if you’re asked questions, you’re likely to answer honestly.”

The tool works as a metaphor in a film suffused with lyrical imagery and sound. Oppenheimer conceived of the soundtrack’s layered recordings of crickets as a ghost chorus, while solitary glimpses of a grassy landscape or birds flocking across the night sky provide reflective interludes between stomach-knotting encounters and the intense emotions evoked by Rukun’s family.

“Every single one of those beautiful shots speaks poetically and directly to his ideas,” said David Wilson, co-founder of the True/False Film Fest in Columbia, Mo., which celebrated “The Look of Silence” by giving Rukun a $35,000 “True Life” prize to open his own brick-and-mortar optometry shop in the town where he relocated after the film was shot. Although a vocal advocate for the nonfiction avant-garde, Wilson praised Oppenheimer for matching a creative vision to a subject of geopolitical significance. “You don’t get to go anywhere you want to go. You have to bring a certain rigor.”

Anonymous, a co-producer and assistant director of the film — and one of many on the Indonesian crew whose real names do not appear in the credits — describes Oppenheimer as “very spirited . . . passionate, and also he has lots of patience,” he said. “You need to wait for the moment, to make it happen, and get the right material — not only the material for the film, but also the truth, the real thing that we want to capture.”

The key scene in the film comes from a series of videos that Rukun made with a camera that Oppenheimer gave him. It occurs near the end of “The Look of Silence,” and it is the most heartbreaking moment in a story packed with tragedy. Rukun’s father has forgotten where he is and crawls through a courtyard, deaf and blind, terrified that he is among strangers. It was the image that conjured the rest of the movie.

“Adi told me, ‘This is the day that it becomes too late for my dad,’ ” Oppenheimer said. “He’s forgotten Ramli. He’s forgotten the son whose murder destroyed his family’s life. But he hasn’t forgotten his fear.” At that point, the filmmaker said he decided that the film shouldn’t be about the nervous co-existence of survivors and perpetrators, but rather “a kind of poem about memory and oblivion,” with Rukun and his family as its intimate focus.

“It’s not a window into some far-off place with people you know little about,” he said, “but a mirror in which we see ourselves.”

“The Look of Silence” opens in Washington on Friday at the E Street Cinema. Joshua Oppenheimer will be on hand Friday for a Q&A after the 7:15 p.m. screening and to introduce the 10 p.m. screening.

Dollar is a freelance writer.