NEW YORK, NY.- Between the jangle of keys and the beeps of walkie-talkies, the men watched.

The occasion was an advance screening of the new A24 film “Sing Sing,” and at the prison it’s set in, the men were taking in a fictional version of their lives.

Amid a heat wave, the audience — a mix of the studio’s guests and incarcerated men in hunter-green pants — crowded into the correctional facility’s chapel-turned-cinema. With the sun streaming through a stained-glass window of Christ kneeling before the cross, the viewers fanned themselves with paper plates.

It was the first time Clarence “Divine Eye” Maclin had been to the prison in Ossining, New York, since 2012, when he finished serving more than 17 years for robbery.

While incarcerated, Maclin had starred as Hamlet in the prison’s makeshift auditorium. Now he was free and returning for his screen debut. He entered the chapel with a grin and a triumphant bounce.

Based on the work of the nonprofit Rehabilitation Through the Arts, “Sing Sing,” directed by Greg Kwedar, follows the production of a prison troupe’s first comedy, a fever dream of a play featuring time travel, ancient Egypt and Shakespeare. Maclin and recent Oscar nominee Colman Domingo star as fellow prisoners alongside Paul Raci (also an Oscar nominee) as their earnest director.

The surprise of “Sing Sing,” which hits theaters Friday, is not that its subjects are showcased in their full humanity in a genre that’s typically played for violence or laughs or both, but the makeup of the cast. The big reveal comes as the credits roll: 13 actors — a majority of the cast — are former convicts who had themselves participated in the rehabilitative theater program.

To step into their roles, the actors had to not only mentally return to who they once were as inmates, memories most had sought to put behind them, but also literally step back into prison.

The film was shot in the summer of 2022 at the now-decommissioned Downstate Correctional Facility in the Hudson Valley. There was no air conditioning, as is typical of most New York state prisons.

“The first thing you notice is the air and the lack of it,” Domingo said in an interview. “Inside those walls, I really felt like I could not breathe. It’s by design. You get lost.”

Most of the actors thought they would never again return to a correctional facility, let alone wear the green prison-issue uniforms. Many hadn’t worn the color since their release — not even in a pattern.

And in a dismaying twist, most of the actors had themselves been detained or processed through Downstate, the very facility that had become their movie set, a haunting reminder of their past selves and an opportunity — a calling, some said — to send a message.

“You’re going back into, basically, hell,” Maclin, 58, said in an interview. “Going right back in. Voluntarily stepping into hell.”

Worn as a costume, the prison pants seemed to itch a little more than he remembered, Maclin said. But the responsibility of the mission outweighed his discomfort. He had a purpose: “The chance to give those people that are still in the position I was in, in those cells, even a modicum of inspiration and hope and say, ‘Listen, this doesn’t have to be your life forever. Mine changed; maybe yours could change too.’”

Kwedar approached Domingo about the role of John “Divine G” Whitfield, a founding member of the theater program who maintains, as does the real Whitfield, that he was wrongfully convicted of murder. There was no script or set timeline, and only Maclin was on board. Kwedar had written “Colman Domingo as Divine G” in his journal, so the fact that Domingo was interested amounted to something of a manifestation.

Kwedar presented his vision and his source material: a 2005 Esquire article by John H. Richardson, “The Sing Sing Follies,” about the making of the play, maniacally written in four days by teaching artist Brent Buell (Raci).

Domingo was in, but he had only one window available for shooting: 18 days in July between finishing “The Color Purple” and going back to set for “Rustin.” Kwedar took it.

“We made this film as if it was going to be our last film,” Domingo said.

Raci, too, was in — “from the first 30 seconds,” he said. “If anything, it was a spiritual happening,” added the actor, who spent decades working as a courtroom American Sign Language interpreter. “Everybody’s spirit was there to do a job.”

Domingo concurred: “We made it together in a very loving, equitable way.”

He meant it literally.

Under a parity model instituted by Kwedar and his writing partner, Clint Bentley, everyone on the cast and crew received the same pay rate, from Domingo to the production assistant. In addition, everyone shares equity.

“The only difference in someone owning more or less in our film as an artist is time,” Kwedar said, meaning how long they spent on the project. “We have over 80 profit participants on our half of the movie, and they have that equity for life.”

Over two months and a handful of video calls, Kwedar and Bentley met with Domingo, Maclin and Whitfield, who was also released from Sing Sing in 2012, to craft the script, building out a story of brotherhood against the backdrop of the theater program’s only comedy in its 28-year history.

“It felt so cinematic, the playfulness of that wacky, strange play against such a dark environment,” Kwedar said. “And the juxtaposition of those two things felt kind of like life to me.”

On set, the actors exchanged tips. Domingo would dial Maclin back from projecting his voice for a stage performance to a more intimate dance with the camera; Maclin would call out Domingo on behavior unrealistic for a prison.

“We’d be accountable to each other for our own expertise,” Domingo said. “They were experts in a way that I wasn’t. There was a beautiful blending for us.”

On the first day of shooting, Sean “Dino” Johnson, who served 15 years at Sing Sing for drug convictions, was awash in emotions, flashing back to nearly two decades before, when he was released in 2004. “Prison is a very morbid place, but believe it or not, I found my freedom behind the wall with the arts,” he said, adding that for the film, “my only ritual was a prayer to be able to show up with honesty and to be able to walk away.”

After a particularly difficult scene in which Johnson’s character recounts witnessing a man get sliced “ear to ear,” Kwedar began to cry.

“He hugged me, and I’m like, ‘Did I do something wrong?’” Johnson said. “I had to go outside and just sit in a chair in the sun and wind myself back down.”

To provide support during shooting, the production hired a therapist who specialized in working with incarcerated people and their loved ones, but catharsis often came from filming together.

In many scenes, Raci’s character guides the troupe through meditations. (“Close your eyes and go to your most perfect spot, most perfect moment.”) Both his facilitation and the group’s responses were improvised, transmitting raw emotion in real time, each man drawing from his own hard-learned serenity.

“The stark reality of where we were and what we were talking about was always with us,” Raci said. “This was not a Hollywood set; this is the real thing.”

At Sing Sing, the Metro-North Railroad barrels through the 75-acre facility, a surreal reminder of a world just out of reach.

Sitting in the second row of the chapel, Maclin rested a red cap on his thigh. To his left were the visitors he had arrived with; to his right, the men of Sing Sing, with whom he would once have sat; in front, himself, on the big screen.

“I always knew I wanted to act,” he said, adding that he never imagined he would star in a movie. “I thought I would be doing it for free somewhere.”

As the film ended, the incarcerated men leaped to a standing ovation. Once the screen went to black, a microphone stand was assembled, and the floor was opened up for questions from inside and outside the community. The evening was running ahead of schedule.

After two questions, several hands shot up, but suddenly the microphone was packed away. Time was unexpectedly up.

As the visitors stood and gathered their belongings, the men were called, cell block by cell block, and filed into a line. An officer called out, “A block,” and they were led out, one after another, until the last pair of green pants disappeared from view.

This article originally appeared in The New York Times.