During a fight scene in the newly released action-thriller “Peppermint,” Jennifer Garner and a cadre of bad guys fall face first into Skid Row’s notoriously filthy streets. 

“There were two smushed rats right next to us,” the actress recalled with a laugh. “Squished, dead rats. (The film crew) was like, ‘We cleaned the streets. Don’t worry, you can fall face first.’ And then we did and they were like, ‘Oops, sorry!’”

“Peppermint” stars Garner as a woman bent on revenge after her husband and daughter are gunned down in front of her. Riley North, a suburban soccer mom turned vigilante, marks the actress’ first action role since ABC’s spy drama “Alias” went off the air in 2006.

Garner says she’s been considering a return to action for a long time.

“There’s this whole skill set that I had developed and hadn’t used in all this time,” she said. “I just felt ready for it.”

In addition to bringing her back to the genre that made her famous, the film also reunited Garner with stunt performer Shauna Duggins, who has been doubling for the actress since the earliest episodes of “Alias.”

“When Jen called about this one, it was like, ‘Wait, hold on. I’ve been waiting for this phone call for 10 years! I’m so excited!’” said Duggins.

The two describe their working relationship as a “weird connection,” with Garner likening it to “meeting a sister at a point in your life.”

“Shauna kind of becomes my director through the action scenes,” she said. “It’s like we’re talking about the character at the same time that we’re talking about what’s going to be a good hit on camera.”

“It’s like going home,” Duggins agreed. “You’d never meet somebody that will work harder than Jennifer. She will step in and do whatever it takes to make that character.”

The last time the two worked together was on the 2007 action thriller “The Kingdom.”

“Our relationship on set is so special, to have gone this long without working together just felt crazy,” said Garner.

They were both drawn to this film because the plot drives the action, rather than the other way around.

“I love real action instead of an explosion for the sake of an explosion,” said Duggins. “I love when it tells the story. And that’s what ‘Peppermint’ is.”

The real deal

“It’s not CGI, it’s us,” Garner agreed. “It’s not in front of a green screen. We actually shot it.”

Despite the close run-in with the rats, Garner says she loved shooting in skid row.

“I like shooting action,” she said. “I mean, I got my ass handed to me a couple of times … “

“Yes, you did,” Duggins chimed in.

“But I like that full expression of emotion and of a scene,” Garner continued. “Action has to be driven by the drama. It’s not like you just stop and do a dance break. Whatever has happened to the character has to be so dramatic and the stakes have to be so high that she has no choice but to start fighting or to pull out a gun.”

“When you watch it, even though she’s killing and hurting people, you’re still rooting for her,” agreed Duggins. “You still want Riley North to win. So the action and training for that had to be that style that’s quick and efficient. It’s not big, pretty, high kicks — it’s getting back to the base.”

Training for the film included three months with personal trainer Simone de la Rue, boxing and Krav Maga before another three months of shooting practice.

“She was at the range training with the guns and switching from handguns to fully automatic and back and forth, pulling them out and re-holstering them,” said Duggins. “And she went out to the range with the Navy SEALs several times.”

“Five times, yeah,” Garner clarified. “Five whole days.”

“The training was hardcore,” she added. “It was just plugging myself back into the stunt community that I’d been away from for so long. Shauna is a stuntwoman, she always stays at this peak level of athleticism. But for me, I was in good shape, but to go from being just a person in good shape to being at this level is just an enormous amount of work.”

98 percent of the stunts

Despite the intensity of training, by Duggins’ estimations, Garner performed 98 percent of her own stunts.

“There are four shots that I saw that weren’t me and I just was flat out … I’m too old to have to rehab what this would be,” Garner said. “I’ve lost that body sense.”

“But I think also, too, there’s just those rare occasions that you go, ‘She can do it, but is it worth it?’” said Duggins. “Because she has to then go do a 10-page dialogue scene after that.”

In a full-circle career moment, Garner will also make her return to television next month in Lena Dunham and Jenni Konner’s “Camping” on HBO.

“I always said I would go back to TV because my happiest experiences and relationships come from ‘Alias,’” said Garner. “But I do love the cycle of a movie. My idea of TV is so extreme because ‘Alias’ was such an extreme experience. I can’t imagine going back to that as a mom of three.”

She allows that the premium cable schedule of “Camping” is a version of TV that’s more manageable for where she is in life now.

“It was the same length as a movie and it was really intense, but I wasn’t in everything,” she said. “I had days off where I could run because I had a kid graduating from elementary school and I was one of the head room moms. There was a lot going on. But I love, love, love the excitement of getting a new script when you have a great group of writers.”

If you go

PEPPERMINT

R, 102 minutes

Playing at Waterford, Stonington, Westbrook, Lisbon