Casey Affleck got Matt Damon to star in 'The Instigators' by asking his wife

What if your therapist was so committed to your well-being that they were willing to put themselves in the middle of a criminal caper in order to keep your sessions going?

That offbeat premise, which anchors the heist dramedy "The Instigators" (streaming now on Apple TV+), convinced Matt Damon to get on board the project co-written by his good friend Casey Affleck.

Well, that and a nudge from Damon's wife of nearly 20 years, Luciana. Or so word has it.

"Wow, word travels," says Affleck in mock shock. "But, no, that is not an exaggeration. She did help."

Damon shrugs and smiles. "My wife is a lot smarter than me."

Affleck can't resist. "Well, that also is not an exaggeration."

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The two old friends break up laughing. But Affleck, 48, who co-stars in "The Instigators" along with Hong Chau, 45, says in a joint interview with all three actors that he is always trying to get his Boston buddy to work with him, at least when Damon isn't planning something with Affleck's older brother Ben, 51. (The duo most recently teamed up for the Nike tale "Air," and together run the production company Artists Equity.)

"We're always looking for things to do together," says Affleck. Then he pauses. "OK, so maybe it's 70/30 me looking for something to do with Matt. I sent a lot of things to Matt, and somehow he just takes a really long time to get back to me."

Damon waves off the joke and gets serious.

"It is such an advantage to have someone you really admire and trust who happens to be an old friend thinking of you because we're all just making it up as we go along," he says. "You're always asking (of a project), 'Does this work at all, does this work for me, does this work for me at this point in my career?' It's not easy. But when you can align, it's just beautiful."

There was a lot of familial aligning going on with the film. Damon's oldest, stepdaughter Alexia Barroso, 25 (the couple has three other daughters, all teenagers: Isabella, Gia and Stella), helped with cinematography. And Luciana takes her first official credit as a producer.

"Luciana's helped behind the scenes on every movie I've done since we've met, uncredited, and she wasn't going to take a credit here, but the other producers said they'd withhold their names if she didn't this time, which was really nice," he says.

While soundstage work for the film was done in New York, all the exteriors were shot in Boston, which doubtlessly provided thrilled locals the opportunity to salute the homegrown stars.

"No," Affleck deadpans, "no one was coming over to visit, maybe they're just used to us."

Chau rolls her eyes affectionately. "He's being modest, a lot of people were stopping and honking during filming."

Affleck throws on a heavy Boston accent: "Yeah, they were nice, saying things like, 'Get outta here, Hollywood! You think you're a big shot!?' "

Chau cracks up, something she doesn't do much of in "The Instigators" as committed therapist Dr. Donna Rivera, who is concerned about the mental stability of Damon's character, Rory.

Her sober delivery actually provides a lot of the humor in the film. Imagine a serious therapy session taking place with Damon and Affleck's characters as they evade dozens of police cars who are chasing their badly damaged BMW through the streets of Boston.

"I did not set out to play this for laughs," says Chau, who garnered an Oscar nomination for her role in 2022's "The Whale."

"But it just unfolded naturally when they took this buttoned-up psychiatrist out of her office and put her into this car," she says.

Affleck looks at his co-star with pity, recounting how the car chase scenes were staged with a gimble launching the prop vehicle to and fro violently.

"I was pretty sure you were going to have to go into therapy after we shot the movie," he tells her.

Chau laughs. "Yes, true, especially since I'm not the best traveler in a car," she says. "I was nervous, so I thought, 'Just breathe and go with it.' "

That pretty much sums up the attitude on the set. While Affleck had written a tight script (along with Chuck MacLean), many of the more memorable moments were improvised, says Damon.

A good example happens late in the movie when nice-guy burglars Damon and Affleck find themselves in the decimated offices of Boston's corrupt mayor (played by a garrulous Ron Perlman).

Also on hand is Chau, in a bulletproof vest and helmet, still trying to get Damon to open up about his feelings, despite a SWAT team being on the way. Sitting nearby is the mayor's deputy, Alan Flynn (Toby Jones).

"So you've got Hong talking to us two quite seriously, and suddenly Toby (in an improvisational flourish) reaches for a drink and starts to get involved in the therapy session," recounts Damon.

"And suddenly, Casey goes, 'Alan, you're not a part of this,' meaning, stay out of our session, which Casey really isn't supposed to be a part of anyway. But he now loves the idea of being in therapy because his character is so self-centered."

Damon laughs at the memory.

"It was a two-count thing where Casey said it, and a moment later everyone just doubled over laughing. It's those extra moments that sometimes just happen that are wonderful. And a lot of this movie was like that."

This article originally appeared on USA TODAY: Matt Damon, Casey Affleck improvised this 'Instigators' moment