It had been the plan to show the 2020 limited series “I Know This Much Is True” in a movie theater when it debuted, with screenings in New York City, Los Angeles and Connecticut accompanying its launch on HBO.

Those in-cinema plans were scrapped when COVID hit. But “I Know This Much Is True” debuted on HBO in May of 2020, to considerable acclaim. Mark Ruffalo — who plays twin brothers, one of whom has schizophrenia — won multiple awards for his performance, including an Emmy for outstanding leading actor in a limited series or movie.

And now, Ruffalo, the movie’s writer/director Derek Cianfrance, and Wally Lamb, who wrote the novel on which the series is based, will all be at the Garde Arts Center in New London next week for screenings of “I Know This Much Is True.”

Lamb, who grew up in Norwich and still lives in northeastern Connecticut, will lead an audience talk with Ruffalo and Cianfrance.

In a phone interview last week, Cianfrance says, “I can’t wait. It’s always been my dream to show this thing on a big screen, and that theater, I’ve never been to it, but it seems like such a beautiful, beautiful spot.”

Cianfrance, whose other credits include the feature films “Blue Valentine,” “The Place Beyond the Pines” and “The Light Between Oceans,” says they wanted to give people an opportunity to see “I Know This Much is True” on a movie screen because they felt as if they were making a film.

The star and the themes

Discussing what drew him to the “I Know This Much Is True” project, Cianfrance says the first thing was the possibility of working with Ruffalo.

“He was always one of my favorite actors. I had spent like 12 years trying to make ‘Blue Valentine,’ and there was a moment in there when I tried to see if Mark Ruffalo would be a part of it, would be the star of it,” Cianfrance says. (Ryan Gosling ended up playing that part in the 2010 release.)

When Cianfrance and Ruffalo met at the 2012 Sundance Film Festival, they chatted and made a pact to work on something together someday. They stayed in touch, and around 2015, Ruffalo told Cianfrance he had gotten the rights to “I Know This Much Is True” and asked if Cianfrance would consider adapting it.

“It was a yes for me immediately just because I wanted to work with Mark and because the themes he had told me about that were in the book were very alive in my work — themes of family and intergenerational trauma, of legacy, of forgiveness, of mental illness, all things that I’ve dealt in my movies before and that drive my life as well. … Additionally, I come from Italian-American ancestry, and I felt like Wally’s portrait of the Italian-American experience was really in keeping with my own,” he says.

Weakness into a superpower

When the possibility of adapting and directing “I Know This Much Is True” came up, Cianfrance hadn’t read the book, although his mother was a big fan.

He thought the 1,000-page novel looked “just intimidating – so massive.”

Reading in general had been an intimidating prospect for Cianfrance. He says he couldn’t really read when he was in high school; he had an undiagnosed learning challenge that he hid from everyone. He managed to ace English classes and to nab an award for most valuable English student in his senior year, despite not having read any of the books.

“I developed my weakness into a superpower, and that superpower was to be able to intuit stories and to pay attention and to understand things on a different level. I knew what happened in the books that we were asked to read in class. (But) if I sat down to read them, it would be an hour, and I’d be on page one and not know anything I was taking in,” he says.

“In the time since then, I have attacked my challenges and worked on them and tried to strengthen them.”

He listened to the audiobook of “I Know This Much Is True” about eight times. After that, he was able to read the book. It was about a two-year process to internalize the tome.

“It came to the point where I had kind of memorized it, before I had put any words on paper,” says Cianfrance, who wrote a 377-page script from the 1,000-page novel.

He had a meeting early on with Lamb and says, “Wally was so generous with me with his work. He basically told me, ‘Make it your own.’ It just felt like a perfect situation, to make something that was personal but it had Wally’s brilliance kind of leading the way with his characters, his themes, the exploration of this legacy.”

A trip to eastern Connecticut

Before they started shooting, Cianfrance and Ruffalo visited Lamb at his home and traveled with him to the places in Norwich and around the area that inspired various parts of the book.

“It was amazing to get his perspective on it. Originally, I wanted to shoot there, but because of tax credits, shooting in Connecticut proved just financially impossible for us,” Cianfrance says. “So we kind of went on the longitudinal lines west just a little bit and found Poughkeepsie, which felt to me like it was socioeconomically very much the same place as those towns in Connecticut.”

Lamb was onboard for a few location scouting trips and visited the set for several days of filming.

“He always felt just like a ballast for me. … Wally’s just such a generous human being, and he was always supportive of what was happening,” Cianfrance says.

Taking on two roles

One of the central questions of making the film was how to shoot Ruffalo as each twin.

“I told him, if we were going to do it, we’re not going to make it a trick. That was the biggest challenge to me — these two characters, they were identical twins, but how do you do it in a way where you can show that they’re different people?” Cianfrance says.

They decided to shoot it in two pieces — Dominick first, then Ruffalo would get several weeks to do a physical transformation while Cianfrance shot other parts of the movie, and then they would film scenes with Ruffalo portraying Thomas.

“We started thinking about, ‘OK, who is Thomas going to be?’ Thomas has been in and out of institutions, he’s been on all these drugs. He’s going to look different than Dominick, first because of the drugs he’s taking, he’s going to have more water weight, so he’s going to be heavier. We started talking about how do we shoot this in a way where you can transform over time?” Cianfrance says.

“Basically, what we did is we had Mark lose 20 pounds to play Dominick. He was on like a 1,200-calorie-a-day diet. I was having him do 50 pushups before every take in the film. He was just this engorged, breathless chest-puffed-out, masculine, toxic, enraged guy who was just out of control and trying to fix everything in his life,” Cianfrance says.

Then, Ruffalo went away for six weeks, during which he consumed 4,000 calories a day (working with a nutritionist to make sure he was doing it safely). He gained 40 pounds, but it wasn’t easy. Ruffalo threw out his back, had trouble sleeping and was generally miserable, Cianfrance says. He asked Cianfrance if he could just, say, wear a suit with stuffing instead of continuing to gain pounds. The director dissuaded him.

“I knew when he was Thomas, when he had a different weight on, it would change his confidence, it would change the way he would breathe, it would change the way he would walk. … Just like he was enraged as Dominick, there would be something that would happen,” Cianfrance says.

In the meantime, Cianfrance brought in another actor, Gabe Fazio, to play the brother Ruffalo wasn’t at any given time, to provide him with a scene partner.

As a director, Cianfrance didn’t want to do a lot of split scenes featuring Ruffalo playing both roles at the same time. He took inspiration from the Michael Mann movie “Heat” in which Robert De Niro and Al Pacino are in the same scene, but the camera cuts between them. The idea is they are flip sides of a coin.

“I was thinking, ‘That works. Why do I have show audiences the tricks?’” Cianfrance says.

Becoming Thomas

When he was playing Dominick, Ruffalo would be the first onset, shake everyone’s hands and look them in the eye, and never go back to the trailer, Cianfrance recalls. He was basically one of the crew.

Then, he took the six weeks off to transform into Thomas.

“All of a sudden, we’re waiting for him to show up on set. … I went out to this trailer to visit him. I knocked on his door and there was this small voice inside, and he was terrified,” Cianfrance said. “He didn’t know what he was going to do, he wasn’t confident in his performance. … He was so insecure. I spent an hour with him in his trailer trying to talk him out.”

Cianfrance eventually showed Ruffalo a bit of the documentary “The Devil and Daniel Johnston,” about musician Johnston’s struggle with bipolar disorder. Watching Johnston gave Ruffalo the courage to go film.

The director and star walked together onto the set, and Cianfrance says, “It was like wind, to feel the mood change of the crew, because everyone’s breath was taken away. They were like, ‘Who is that guy? Mark, like, where is he?’ … It’s not like this Method actor thing. He just had changed, he had really changed.”

It happened to be Sept. 11, and the first assistant director suggested everyone take a moment of silence to remember the tragedy.

“Before we knew it, there was this voice that said a prayer for America, and it was Thomas, and you started to think about Thomas and what did he want, what was his desire, his need, his want in the show — why does he cut off his hand in the first episode? He’s trying to end the war, he’s trying to end the U.S. reliance on oil, on fossil fuels. This takes place in the ‘90s so he’s basically trying to end the Gulf War. He’s trying to make it so Sept. 11 never has to happen. And no one’s going to listen to him,” Cianfrance says.

Everyone was hushed as Ruffalo, sounding very much like Thomas, prayed for America.

“I Iooked at my DP (director of photography) and motioned to start rolling, the sound person started rolling,” Cianfrance says. “(Ruffalo) finished his prayer, and we just effortlessly moved into Thomas. Thomas was alive in that moment. We were in awe watching.”

k.dorsey@theday.com

IF YOU GO

What: Screenings of “I Know This Much Is True”

Where: Garde Arts Center, 325 State St., New London

When: 7 p.m. Wed. hosted by Wally Lamb; 7 p.m. Thurs. and Sept. 23 with Lamb hosting an audience chat with star Mark Ruffalo and director Derek Cianfrance

Cost: $24 for Wed., $48 for Thurs. and Fri.

Contact: (860) 444-7373, gardearts.org