While starring on HBO’s “The Deuce,” Maggie Gyllenhaal used to write “long essays” about why she believed certain scenes shouldn’t be cut. She had always been fascinated by the editing process in film and television, something she was rarely involved in as an actress. She sought more creative control.

That is exactly what she achieved with her directorial feature debut, “The Lost Daughter,” an adaptation of the Elena Ferrante novel now streaming on Netflix. Gyllenhaal, who also wrote and produced the thriller, tweaked certain elements with the pseudonymous author’s blessing; the story pulled from a Neapolitan novel now takes place in Greece, where a middle-aged, divorced professor, Leda (Olivia Colman), encounters Nina (Dakota Johnson), a young mother from Queens, while on vacation. Nina’s daughter loses her doll at the beach, and the emotional fallout lasts days, exhausting Nina and reminding Leda of her own struggles early on in motherhood.

Spliced throughout the film are Leda’s memories from roughly 20 years ago, in which the character is played by Jessie Buckley. Viewers witness both young Leda’s tenderness and her frustration, sometimes driven by ambivalence toward motherhood. She begins an affair with another professor (Peter Sarsgaard) after he praises her work as an English-Italian translator. Slowly, an uneasiness builds both in Leda’s present day and in her recollections, adding a layer of suspense to her otherwise innocuous interactions with the other vacationers.

The delicate tone and layered themes of “The Lost Daughter” make for a tricky adaptation. But Gyllenhaal pulled it off, as her film premiered to critical acclaim. In conversation with The Washington Post in January, Gyllenhaal, 44, spoke enthusiastically about why she adapted the novel, how she navigated the transition to directing and what she makes of audience reactions to the film.

“I was like a kid in a candy shop,” she says. “Like, what? I can just explore here and do whatever I want?”

(The conversation has been edited and condensed for clarity.)

Q: Why tell this story for your directorial debut?

A: It’s a movie about trying to embrace and normalize the huge spectrum of feelings that are inherently a part of being a parent. We’ve been told that only a few things are really acceptable in terms of our feelings about parenting, and yet parenting is, I think, the most complicated, incredible and also the biggest challenge that there is. It only follows that you would have a massive spectrum of feelings about it.

Leda, of course, is really extreme, and she does something that’s really aberrant and that isn’t in the realm of possibility for me. But if we’re talking about the world of the mind — which, I think the movie lives in … [and] is part of what compels me about it and what compels me about the book — as a fantasy, as an idea, as a possibility, it’s an interesting thing to think about.

Q: How much more did you feel you were able to accomplish as an artist with this level of control?

A: I’ve never been an actress who wanted to be told, “Stand here, and this is what this scene is about and this is what I want you to articulate.” I’ve been much more interested as an actress in real collaboration.

But I did find as an actress — often, not always — that only a percentage of what it was I wanted to express actually found its way into the movie. And I got used to that. That’s part of the gig. But I think I was rarely really satisfied, and that was definitely one of the things that pushed me into wanting to write and to direct.

Q: Did you ever find yourself in a position in which you were working with actors and realized that you were on the flip side of things, and able to work with them in a different way?

A: I was very aware of that always because that’s where my expertise is. I spent so much time as an actress and I often remember being in situations with directors where I thought — well, it’s almost like the feeling of being a child when there’s an injustice. You’re like, “When I grow up, I will never, ever do it like this.” I was very conscious and aware of that. But I also work with actors all the time as an actress, and so I know how to interact, how to help someone feel free. I know what helps me feel free. Of course, with every actor it’s different.

Q: How did you approach the pacing of a movie that is more an exploration of someone’s interior than it is, like, an A-B-C plot?

A: As a writer, and then also in the editing room, I don’t know — I could just sort of feel the pace. We got some notes early on that the beginning felt slow, and we experimented with taking a whole day at the beach out. It really didn’t work. And the reason it didn’t work is because the movement through this thriller is in this woman’s mind — you need to give a little space for the audience to understand that, and to get inside her. You can’t push them in. You can’t kick them in.

I can feel pretty clearly when sometimes something goes on a little too long and it turns from being very truthful to sentimental.

Q: It’s great when scenes cut at the point where it’s clear what the characters are saying or what their words represent, but there’s space left for the viewer to interpret them as well.

A: I so agree with you, and that’s the kind of filmmaking that I respond to. Ideally, what you’re doing is you’re engaging people and you’re asking them, “How do you feel about this? Who do you think that is in a relationship?” I remember someone saying to me about Callie early on — the pregnant sister-in-law — someone saying, “You might need to work on her a little bit because it wasn’t clear whether or not she was ominous or friendly.” I was like, “No, that’s great.” That’s so many people you meet in your life, where you’re like, “I’m not sure if that person is ominous or friendly.” And then you’re engaged. Is she a friend or foe, you know?

Q: I found the dynamic between Callie, Leda and Nina fascinating; Callie is almost a foil for the other two. How did you approach collaborating with the actresses?

A: If the idea is to get to a place where you’re exploring things you’ve never explored before, where you’re in an unknown, exciting territory, how you help someone get to a place where they feel free is going to depend greatly on the person. For Dakota, she and I worked very specifically through the scenes, almost in a very classic Actors Studio type way. “What’s the event of the scene?” “What is it that you need, and what is the obstacle to get it?”

And with Olivia, it’s funny because I was kind of misquoted as saying we barely talked to each other recently, which kind of pissed me off. We were really working in the most intimate way for a very long time. What I meant by whatever it was I said was that Olivia did not want to talk specifically about the scenes, about the characters. And I completely understand that. She’s not someone who communicates in that way. Most of the communication I had with Olivia was talking about something up here [gestures up high] and really, underneath it, we were having a secret conversation about the scene.

Q: There had to be somewhat of a tie here between Jessie Buckley and Olivia Colman, given that they’re playing the same woman at different points in her life. What was it about Buckley that you were drawn to?

A: I cast Olivia first, obviously, and then I saw [Buckley] in “Wild Rose” and she felt like a kindred artistic spirit. Dakota and Olivia — who I think are just brilliant, I just love that triumvirate of actresses — are very different than me. Jessie, I feel like we kind of speak the same language.

In terms of Olivia and Jessie, the biggest risk in taking on this adaptation was the 20-year age gap. Certainly in a novel it’s fine, because you’re imagining everything. But cinematically, how do you do that and not have it be goofy? You could age an actress, but it’s so rare that that doesn’t feel so disingenuous. And here, in a movie where we’re asking people to look at really painful, truthful things, we can’t offer them anything that’s fake.

If you’re not 4 years old, you’re going to know that these are two different actresses — two fully formed, formidable, brilliant actresses. Olivia Colman is not Jessie Buckley. And so we can just forget about trying to trick you and just agree as adults to make the poetic agreement between us that for the purposes of telling this story, these two women are going to portray the same person. Then, you’re totally free. You don’t have to worry about having an eye twitch or a neck tattoo or something.

Q: You also worked on this project with your husband, Peter Sarsgaard, whom you’ve acted opposite before. What was it like to direct someone you know so well?

A: In some ways, it’s the same. I wanted Peter to feel respected and seen and loved and free, which is the same thing I wanted for all my actors. I had worked with him twice as an actress. What that did — doing these two Chekhov plays over and over again — was, it really solidified a mutual respect, artistically, between us. I think you can love someone and not like their work. I do. I think if Peter were a terrible actor, I would still love him. But it happens that I think he’s a brilliant actor, and he knows that I do.

“The movie is asking a difficult thing of people, of men and women, which is to be able to hold in your mind a mother who is many many many complicated things… who is good and bad at the same time.” (Washington Post Live)

Warning: The rest of this interview contains spoilers for the ending of “The Lost Daughter.”

Q: Going back to not going too far in a scene, and allowing viewers to make up their minds for themselves: What attracted you to the ambiguous ending, as a storyteller?

A: What do you think is ambiguous about it?

Q: Whether Leda lives or dies. I find her fate to be ambiguous. [Note: Toward the end of the film, Nina finds out Leda betrayed her trust and stabs her with a hat pin. With a bleeding wound, Leda gets in her car and crashes it, staggering to the beach right after.]

A: Why do you think — I don’t know …

Q: Do you not see it as ambiguous?

A: I love that people do. I just think it mostly lives in the fantasy world of the audience. If she dies, we’re punishing her. It’s not a punitive movie. It’s really not what we’re doing. To me, this is a woman who is a hero, even though she is someone who has caused probably irreparable damage to both herself and her children. Whatever that means. We cause tiny bits of damage to ourselves and our children all the time. But she really is almost destroyed by it, and I imagine her children, too. But she is a hero to me because she is brave enough to go down into the darkest, most painful, shameful parts of herself and take a look. And that is where the life is.

Read more: