JOHANNESBURG

ON the set of the Australian director Phillip Noyce’s “Catch a Fire” last fall, the mood was as mixed as its cast and crew, a striking microcosm of post-apartheid South Africa. White South African actors performed scenes in English and Afrikaans. Black South African crew members traded information in the 11 languages spoken here. Local white crew members wore blond dreadlocks. And former African National Congress fighters stood in the same room with a retired security branch police officer, uneasily comparing notes on the fine points of torture.

Based on the life of Patrick Chamusso (played by Derek Luke), a black man politicized by injustice in apartheid-era South Africa, and his nemesis, a police colonel named Nic Vos (Tim Robbins), the film opens on Oct. 27.

“You look at the set and it tells the same story that you’re telling,” said Bonnie Henna, the 26-year-old black South African who plays Patrick’s wife, Precious. “There’s this energy bubbling underneath. This is not some story of long ago, an imagined story. It’s the kind of a story that picks at scabs. It’s picking at the scabs of even those who are telling it.”

Mr. Noyce, whose last two films were “The Quiet American” and “Rabbit-Proof Fence,” arrived here nine months before shooting began. “It took that long to only begin to understand things,” he said, “the history and the culture of both sides. To have the confidence to say, ‘O.K., now I can tell that story.’ ”

The tale of how Mr. Chamusso’s life became a movie began when Joe Slovo, the white chief of staff of the African National Congress’s military wing and later housing minister in the government of Nelson Mandela, told his daughter Shawn, a screenwriter, that she should write a script about this unlikely hero.

“I think Joe was particularly taken by Patrick because he doesn’t fit with one’s idea of a political activist,” said Robyn Slovo, a producer on the film and another of Mr. Slovo’s daughters. Mr. Chamusso was an uneducated man who loved soccer and women and stayed out of politics. But one too many false arrests and brutal beatings turned him into a man capable of carrying out a solo bombing mission at the Sasol oil refinery in Secunda, where he worked. The strike killed no one but sabotaged government-owned interests at the facility. He served 10 years of a 24-year sentence on Robben Island, and was released in 1991 after the fall of apartheid.

“Terrorism is the single biggest real fear in the contemporary world,” Robyn Slovo said. “What’s interesting is there’s not enough time spent looking at why a man would do this. Not all terrorists are the same. But this is our attempt to make an audience identify with a terrorist, there’s no question about it.”

Mr. Chamusso does not accept the terrorist label, however. “I was pushed to do it,” he said.

He had been flown here to the movie set from his rural home 300 miles away, where he lives with his wife and their three children and takes care of several dozen AIDS orphans, many of whom live with them. “I didn’t care about politics,” he said. “I was fighting a government who oppressed me. I was fighting for my rights.”

The filmmakers made it clear that they were interested in telling both sides of the story. The character of the policeman, Mr. Noyce said, had to be “three-dimensional, because the film would be not worthy of being watched if the policeman was just a caricature of a racist.”

As played by Mr. Robbins, the character is a composite of policemen who interrogated and tortured Mr. Chamusso. But the filmmakers hired an ex-policeman named Hentie Botha as an on-set technical adviser.

“You knew in terms of the law this is wrong, but you justified what you were doing with ‘This is for the country,’ ” Mr. Botha said. “Your methods became more extreme, and the more extreme, the more success you had, the more acknowledgment. They might have suspected you’re overstepping the bounds, but what the hell. On the books it looked good.”

Mr. Botha was disarmingly eager to talk about his Truth and Reconciliation Commission hearings, the breakup of his marriage and his post-apartheid religious awakening. Telling an anecdote about how he ordered a female A.N.C. operative to be “eliminated,” he displayed an unsettling intensity.

“He’s in a process,” Mr. Robbins said. “There have been some tense moments in the prep of the film between him and a couple people. Because he has a tendency to rationalize, and some people don’t want to hear any excuses.”

Mr. Robbins said that talking with Mr. Botha and watching 1960’s propaganda films shown to white South African police officers about the dangers of blacks helped him understand the mind-set of his character.

“What is interesting to me about this script is that it poses the question: How far do you go in fighting a noble battle?” he said. “Do you become less noble yourself if you believe your enemy is so nefarious that you must cross the line morally? Is there a direct relation between that and the rise of your enemy?”

Mr. Robbins had arrived a few weeks early to get a feel for the place. “This is a society in transition, and it’s all very fresh,” he said during a lunch break in his trailer. “It’s the exciting thing about it, and it’s the disturbing thing about it. It’s going to be generations before people even understand their own racism. I mean I’m hearing stuff that I heard when I was a kid in the early 60’s in New York.”

Mr. Chamusso is using the money from the sale of his story and his consulting fees to finance his Two Sisters organization, named for the first two AIDS orphans he brought home, and he seemed simultaneously proud, overwhelmed and incredulous that his life had become the subject of a movie. Nevertheless he was taking his role as adviser on the film seriously in a deserted former bank building downtown whose rooms had been converted into a drab police headquarters.

During one interrogation scene of a black suspect, Mr. Chamusso sat in a corner, excitedly pointing out afterward that a detainee would have been naked, his legs chained to the police officer’s desk.

Mr. Noyce decided to leave the actor’s clothes on, but did chain his legs. “When I sit here, it really takes me back to how I was tortured, how I was beaten, how I was made to stand for days without water and food,” Mr. Chamusso said later. It “is painful for me,” he added. “It’s opening a healed wound every time I talk about these things.”

Napthali Manana, one of Mr. Chamusso’s fellow prisoners on Robben Island, who now works for the African National Congress in Johannesburg, was hired as a day-to-day consultant. He talked Mr. Luke through a pivotal scene in which Patrick’s hands are cuffed behind his back and yanked up by a rope, an excruciating procedure that leaves no visible signs of abuse.

“I told him this is so painful, it can even break your heart,” the soft-spoken Mr. Manana said. “Try a little bit to make sure that you feel that pain.”

The filmmakers tried not to pull the rope too tight during the scene. But Mr. Luke, his hair grown into an Afro for the role, said he was having trouble keeping his balance in front of the camera in such an awkward position.

“So I turn to the guy and I say, ‘You’re going to have to pull it, and if I don’t say stop, you don’t stop.’ ” It hurt enough, Mr. Luke said, to make him comprehend the moment that can break a man’s will and make him say anything, guilty or not.

But Mr. Noyce does not dwell on scenes of torture in the film, and he said “Catch a Fire” was ultimately about transcendence.

“South Africa’s recent history is a beacon to the rest of the world in terms of the peaceful resolution of bitter interracial conflict, keeping the infrastructure of the country intact, preserving the rights of citizens on all sides,” he said. “The movie really is about the South African miracle. The moral consequences of that struggle to all the participants, and then how in this society they’ve managed to move beyond that struggle. They live with it, they don’t deny it, but they live together.”