Mark Duplass and Elisabeth Moss (right) in THE ONE I LOVE. (RADIUS-TWC)

Elisabeth Moss, best known as Peggy Olson, “Mad Men’s” buttoned-up but ambitious secretary-turned-copywriter, smiles with her whole face while talking about her latest project, “The One I Love.”

The film, written and directed by newcomers Justin Lader and Charlie McDowell, respectively, centers on a married couple (Moss and Mark Duplass) trying to navigate the growing space between them with help from a quirky therapist. He suggests a retreat, which causes both to consider dimensions they never knew were possible. After getting a taste of the eccentric Charlie Kaufman-inspired powers of the properties’ guesthouse, Moss’s character suggests with a gleeful curiosity that they might explore this new world. If that sounds vague and slightly confusing, it’s by design. The filmmakers don’t want viewers to know much going into the movie, and that sometimes trickled down to the cast.

“The scene where I have to explain to Mark what’s going on in the guesthouse, I walk in and he’s freaking out, and I have to tell him what’s happening — I so barely understood what was happening myself!” Moss enthusiastically explains. It required 10 takes and a combination of Lader’s intricately constructed Albee-esque dialogue and carefully calibrated improv between Moss and Duplass, who’s an accomplished writer, director and producer in his own right. In fact, the genesis of this project was a single sentence he had scribbled down and passed to Lader and McDowell.

“We didn’t want it to sound like improv. We didn’t want to be one of those indie movies where it sounds like everyone’s making it up. I like those movies, but we wanted this to have a more classic feel,” Moss explains. The 32-year-old actress, who’s been in show business a whopping 24 years, had experience with broader improv with Jonah Hill and Russell Brand in “Get Him to the Greek,” but this process felt quite different.

“This wasn’t about making everyone laugh all the time. It was about telling a story,” she says. “Every night, Justin would write the scenes for the next day. We’d sit and go over it. Sometimes it would take 10 minutes and sometimes an hour.” Moss and Duplass would chart lines they would each say. “We just need to make sure we get to this point or hit that emotional beat,” Moss emphasizes. The last 30 pages, she’s quick to point out, are entirely scripted, including her favorite scene, which is impossible to describe without spoilers.

Actress Elisabeth Moss poses for a portrait during the 2014 Sundance Film Festival in Park City, Utah in January. (Larry Busacca/Getty Images)

“You don’t want to know what happens in a movie. You know when you watch a trailer and they tell you the whole movie and you’re totally pissed off? We don’t want to do that to the audience. It’s not like ‘The Sixth Sense’ or anything,” Moss emphasizes.

Moss was particularly drawn to the relationship that’s at the heart of the film, and many conversations during filming were focused on the specifics they were creating along with more general and philosophical ruminations on coupling. “The idea that you present this person in the beginning of a relationship. You bring out all your best qualities, and you’re like 20 percent better than you are. You bring out this shiny version of yourself, but then after four years, you’re more yourself. And whatever that means. How does that affect the relationship, and how do you get back some of that magic you had in the beginning?”

This led to talks about the ideal partner and how a man’s ideal differs from a woman’s. Moss and producer Mel Eslyn represented the women. “One of the big things that we discovered was that men think that women want them to be super cool and slick and smooth, but in reality, women find that creepy and sleazy,” Moss says. Outside the sometimes complicated process of measuring nuance between nice and doting (which is also apparently a turnoff), Moss says sweetly, “We actually just want you to make us laugh and make us feel like you’ve been listening to what we’ve said.”

These revelations (along with shooting) took place in two weeks on an idyllic compound in Ojai, Calif., that doubled as lodging for the cast and crew. The experience reminded Moss of summer camp. “I lived next door, and we all lived around or on the property. We ate dinner together every night. On our days off, I’d wander into the house and people would just be hanging out on their computers or going to the pool.”

While she’d been splitting her time between New York and Los Angeles for the duration of “Mad Men,” Moss is happy to be back on the east coast and in New York, where she moved almost 13 years ago to do an off-Broadway play, Richard Nelson’s “Franny’s Way” at Playwrights Horizons.

It’s been reported that she’s in talks to star in a coming Broadway revival of “The Heidi Chronicles,” but she could offer only a coy smile in response. “I haven’t done anything since I did ‘The Children’s Hour’ in London, and I’m kind of itching to have that experience again. And it means I get stuck in New York for six months, which I love.”

She doesn’t favor Broadway or any medium for that matter. “I don’t care how big it is, how long it takes to shoot or what I’m making. If I think it’s a cool script and story and a character that I find challenging,” that’s all the matters to Moss, who, with two films at Sundance this year (Alex Ross Perry’s “Listen Up Philip” and “The One I Love,” which made its east coast premiere at the Tribeca Film Festival) and three more in the works, is poised to become an indie star, though designing a career is the last thing on her mind.

“Nothing that I’ve ever played could I have ever planned. I never would have said: ‘I want to play a copywriter in the ’60s. I never would have said, ‘I want to work on a miniseries with Jane Campion and play an Australian detective.’ Who says that?” (Lately, the Internet has been abuzz with rumors of her appearing in the second season of HBO’s newest hit, “True Detective.”)

When she was filming “Top of the Lake,” her wind-down routine each night was binge-watching four episodes of “The Sopranos.” “I watched the entire series in like two months,” she declares while citing her love of TV as her favorite form of procrastination.

She’s working on the new sci-fi drama “High Rise” in Belfast and indulging in a show she deems “potentially embarrassing.” “All of my shows are off now or on hiatus. I’ve seen them all, so I’m like ‘Pretty Little Liars,’ you’re up.”

While out one recent night in Belfast, she was surprised by how often she was recognized. “It’s kind of funny for me because it’s just me. I don’t understand why someone wants a picture with me? I haven’t quite reconciled me and that person that people recognize.”

Kompanek is a freelance writer.