In July, New London’s Garde Arts Center was presented with the prestigious Outstanding Historic Theatre Award from the League of Historic American Theatres.

Earlier this week, they yet again demonstrated why the facility is worthy of such recognition by bringing a bit of starshine to the property.

In two-episode increments from Wednesday through Friday, the Garde screened the entire film of the HBO dramatic series “I Know This Much Is True,” which is based on bestselling Connecticut author Wally Lamb’s novel of the same name.

Lamb was on hand to discuss the book and series at Wednesday’s screening. On Thursday, he was joined by the film’s director/screenwriter, Derek Cianfrance, and actor Mark Ruffalo, who won a best actor in a dramatic series Emmy for his portrayals of the story’s trouble identical twin brothers, Dominick and Thomas Birdsey.

The post-screening conversation Thursday, before a nice crowd of rapt fans, comprised 35 minutes of thoughtful, revealing and even lighthearted anecdotes and thoughts from the trio of principals, guided ably through the conversation by the Garde’s writer-in-residence, bestselling nonfiction author Jeff Benedict.

The Garde presentation was the first time “I Know This Much Is True” was shown in a movie theater. The series premiered on HBO in May of 2020 but plans to screen the film in select theaters in early 2020 were canceled due to COVID-19. Lamb suggested to Garde executive director Steve Sigel that the time might be right to finally bring the film to a theater, and a plan was put into action.

“I Know This Much Is True” details the lives of the Birdsey twins; Dominick is a divorced house painter who feels a sort of “survivor’s guilt” because his brother Thomas is an institutionalized schizophrenic. Lamb’s novel is a long, marvelously rich but somber story that bounces back and forth in time and reveals not just the intricacies of Thomas’s descent into mental illness but also Dominick’s own troubled past.

Here are some “greatest hits” from Thursday’s discussion:

Benedict asked Lamb if the novel was autobiographical. Lamb said not too much, explaining there’s no schizophrenia in his family. He did briefly describe a rarely discussed family secret of sorts in which his grandfather tried to kill his grandmother. The incident obviously left an impression on Lamb, as did the subsequent efforts to not talk about what happened.

“There was such a stigma to mental illness at the time,” Lamb said.

Lamb then explained that the actual inspiration for the novel came from his teaching days at Norwich Free Academy. He’d reached out to the public seeking folks who’d lived through the Great Depression to speak to his students about those experiences.

One of the volunteers showed up to class wearing sunglasses and kept his arms crossed. When it was his turn to speak, he took off his glasses and unfolded his arms. He was missing one eye and one hand. The wounds were self-mutilations ― “sacrifices” the man had made to God in hopes that the atrocities of World War II would stop.

Readers and/or viewers of “I Know This Much is True” remember the book’s opening, when Thomas severs his own hand in a public library as an offering to God to prevent the Gulf War.

“(The classroom volunteer) was a religious zealot looking for a flock,” Lamb said. “The students were too freaked to work with him, so I worked with him. He was crazy but somehow noble. A lot of his views weren’t so different than my own.”

Benedict wondered if Ruffalo experienced moments of doubt after filming began; whether taking on two such heavy and intense roles was too much.

“It was very daunting,” Ruffalo said, smiling perhaps because it’s over and he survived. “I did think at one point, ‘There’s no way I can pull this off.’ But by then, we were so far along I had to persevere. I’m also not the most confident actor. I’m always fighting my own self-doubt.”

Ruffalo told an anecdote about approaching the iconic acting teacher Stella Adler and confessing his chosen craft frightened him. Screwing up his features, he approximated Adler’s voice and delivery for her response to him: “Listen, nerves! You listen to me, you (expletive). You’re just part of me, not all of me!”

Laughing, Ruffalo continued, “So you commit yourself at a point beyond which you can’t go back. You throw yourself into the void and hope.”

Cianfrance drew laughter from the crowd after Benedict observed that, because of the dark tone of the narrative, he was surprised a company like HBO would green light such a project. “Well, it was pitched as a comedy,” Cianfrance said. “That’s why there are some fart jokes in there.”

The director went on to say that the darkness of the novel was in fact a major part of what attracted him to the project. “I love Hollywood escape films with these perfect fairy tale arcs, but since I was a kid, those movies left me feeling lonely. My life was very different from what I was seeing on the screen. There were no fairy tale arcs. I wanted to make movies about some tragedy because, ultimately, I came to believe that catharsis through tragedy is just as important in our business as fantasy.”

One of the funniest moments of the discussion was when Lamb talked about a personal bout of intimidation. After the massive and unexpected success of his first two novels, “She’s Come Undone” and “I Know This Much is True,” his agent went to negotiate a contract for a new book and asked for, as Lamb says, “A whole LOT of money. And she got it. I was paralyzed with fear. I believed I couldn’t write anything worth that amount of money.”

He said he suggested to his agent that they return the money. “You’ve already cashed the check,” he was told.

Ruffalo said he felt the same way when he realized the difficulty of playing both Dominick and Thomas. “But not only had they written me a check, I’d already spent it!”

r.koster@theday.com