Much of Edward Berger’s gripping papal thriller “Conclave” unfolds in the shadows. Alliances shift and break in dim stairwells, tense accusations fly in dark corridors and secrets are exposed in the lamp-lit privacy of the papal apartment — all in danger of upending the centuries-old process to elect the next pope. So when a shocking revelation (warning: spoilers ahead!) in the film’s final act and an unexpected tragedy cast a harsh new light on the cardinals in the running, it feels like a dizzying release.

The more progressive Cardinal Bellini (Stanley Tucci) points the finger at traditionalist Cardinal Tedesco (Sergio Castellitto), telling him he should be ashamed of himself. An unflinching Tedesco whips the group into a frenzy with talk of a religious war as former front-runner for the papacy Cardinal Tremblay (John Lithgow) sits back in disgrace and Cardinal Lawrence (Ralph Fiennes) stands frozen in dismay over the proceedings he’s lost control of. Then, Cardinal Benítez (Carlos Diehz) stands up.

Poised and calm, he tells the group, “Forgive me, but in these last few days, we have shown ourselves to be small, petty men, concerned only in ourselves, in Rome, in the election, and in power.”

Appointed by the late pope “en pectore,” or in secret, Benítez’s very presence is a threat to the careful balance of the conclave. In contrast to his counterparts, he radiates a tranquil energy that serves as an antidote to the petty politics and drama playing out among the top candidates. Though he hasn’t campaigned, and while he was completely unknown to the other cardinals prior to their gathering, by the time Benítez addresses the group, he’s the dark horse of the election.

It’s an arresting performance, one made all the more impressive by the fact that it’s Diehz’s feature film debut. At 53 years old, the Vancouver-based actor decided to give acting a try in 2020, appearing in a few short films until booking his breakout role in “Conclave.” Born and raised in Mexico City, he’s worked primarily as an architect (he still works for the same Canadian firm today) for the last 30 years.

De Los spoke with Diehz about his unorthodox journey to the screen, the inspiration for his performance as Cardinal Benítez and finding the confidence to be himself. The following interview has been edited for clarity and length.

Carlos Diehz makes his screen debut as Cardinal Benitez in “Conclave.”

(Focus Features)

Had you ever thought about pursuing acting before becoming an architect?

I’ve always been inclined to the arts since I was a kid — drawing, clay modeling, all that — then, later on, when I realized the people I saw in the movies were performing, they were acting as the characters, I thought maybe I’d like to do that. But I was a very shy kid, a daydreamer. I decided to give acting a try in high school, but the kids in theater were really, really flashy and outgoing, and it was just too much for me. Later, I had a chance to be in a movie as an extra, but when I had the camera in front of me, it was so intimidating. I was given this crazy instruction to stand up and shout all the bad words I knew. I freaked out, and the director said, “OK, never mind. Not you.” They chose someone else. So that was almost my big break. [Laughs]

Why did you decide to give it another try later in life?

Probably four or five years ago, my wife and I became empty nesters, and I wanted to learn to do something new. I didn’t have the time or the money to go back to college, so it needed to be something I could learn on my own. I thought about acting again and decided to give it a go. Then the pandemic hit. Everything was closed, but I found this workshop online and signed up for that. Right off the bat, the coach said, “If you’re doing this just to feel good about yourself or to get a hobby, don’t waste my time and don’t waste your time, because this is the show business. Is not the show charity or the show hobby. Take it seriously.” In the classes, being able to transform into someone else, to channel a different personality, was so much fun that I said, “Yes, this is my new passion. This is what I want.” So after practicing architecture for 30 years — I still am working in architecture — I found this new passion that was so exciting.

On the surface, it doesn’t seem like there would be a lot of crossover between architecture and acting, but do you find any similarities in how you approach them?

I think there are, because both are creative. In architecture, you are meeting a lot of requirements for the client and for the authorities, and you have to meet certain standards. Acting has similar demands. You have your imagination, you put yourself into the character, but you still have to comply with the vision of the director, the technical requirements, and you have to be part of a team. You put a lot of yourself on the line when you portray a character. You don’t transform entirely into someone else, but you’re channeling them through you.

Growing up in Mexico City, were there any actors who stood out to you and shaped you?

The golden era of Mexican cinema was very theatrical. I would admire how Pedro Infante could be this humble carpenter [in “Nosotros los Pobres”], and then he could be a motorcycle policeman [in “A.T.M. ¡A toda máquina!”] Being able to take on those roles with the same charisma was very fascinating and attractive to me.

Casting director Nina Gold has spoken about the international casting search to find Cardinal Benítez. What do you remember about the initial description of the character?

The initial description of him mostly talked about his physicality — that he was a slim, mixed-race guy. My agent thought I was a good fit for it, so she sent out my demo reel, and they invited me to audition. After the first audition, I got the book. I read it twice in the next couple of weeks, so I knew the whole story. And then for the second audition, they gave me the whole script, and I realized it was very faithful to the book, which I was very happy about.

When I read the breakdown, I remembered being 19 or 20, and going through my mystical phase. I was lost, and then I found God, and I just wanted to go out and preach the good news to everyone. When you’re a teenager, you want to change the world, right? So when I read the briefing on the character, I thought, “This is who I would have liked to be if I had pursued a life in the church.” It felt like an opportunity to be that person for a bit, and that felt very, very encouraging.

The casting process took three months, with several rounds of auditions. What was that experience like?

It was really daunting, and there was a lot of self-doubt. I just had to keep trusting the process, and tell myself that they liked me enough to have that first callback, and they liked what they saw enough to invite me back again, and so on. When it came time for the final callback in Rome, I just kept thinking, “Don’t overdo it, just do what you did.” But you’re there with Nina Gold, Edward Berger and the producers. No pressure, right? [Laughs] I had to just keep it steady, follow their direction, and find the sweet spot of the emotion and the timing.

As an actor, you were about to make your feature debut alongside some legendary performers. But as Father Benítez, your presence had to be grounded, and almost free of any doubts. How did you square those realities?

The mindset I had to have was, “I belong here,” even though I was thinking, “Am I going to be able to perform at the level where I can share the screen with these giant actors?” It was a process of building up my self-esteem, and there were a lot of daily affirmations involved. Really, every day, I was saying, “I belong here. I got this role.” Even being in Rome, going to the sets, I had to wake up and do that exercise over and over again, and open myself up to the support and generosity of the other actors. That was unexpected. Not that I thought they would be cold, but they really did help guide me, and that was the best thing of all with this experience.

Also, after being an architect for 30 years, you have to face some really, really difficult situations with investors and authorities, and there is no second take. There’s no reset — you just have to be able to deliver. So in that sense, my experience in architecture was actually really helpful here.

Working alongside veteran actors, Diehz said, “The mindset I had to have was, ‘I belong here.’”

(Kristine Cofsky Photography)

Did the experience of portraying Cardinal Benítez teach you anything about yourself? Did you connect with the character’s struggles in any way?

I think in life, we find ourselves in certain situations where you feel like you don’t belong. Maybe you face rejection, or harassment from other people. You might feel like something’s wrong with you, but you have to build up your character, and find a way to love and accept yourself for who you are. Benítez has achieved that. That’s what gives him the confidence to stand beside these other cardinals and stay loyal to who he is, but also to confront everyone who is missing the point in this exercise of picking the next pope, everyone who’s forgotten the requirements of the robes they’re wearing. That’s the beauty of the character, is his assurance that when he’s on the right path, he won’t back down.

Screenwriter Peter Straughan said that one of the things he hoped audiences would take away from the film would be one of Cardinal Benítez’s lines about knowing what it means to exist between certainties. What do you hope audiences leave the film with?

That everybody has a choice. We all have free will. I think this movie asks you to question the very nature of your soul, your body, your mind, and how you interact with the world around you. Some of these characters have more flexible morals, some of them choose to stick to the rules, and someone like Benítez decides to embrace his nature. He believes that he was made by God’s will, and he sticks to that. Maybe that’s what makes him more compassionate, more loving, more caring. The movie is about the doubt, the leaps of faith that keep each of them moving forward, and the choices they make to either embrace their nature or turn away from it.

Your character has several very moving scenes one-on-one with Ralph Fiennes’ Cardinal Lawrence, but I think one of the best moments in the film is when Cardinal Benítez addresses the rest of the conclave. How did you prepare for that scene?

I’ll tell you the difference in inspiration versus execution. The inspiration going into it was [Franco Zeffirelli’s 1977 TV series] “Jesus of Nazareth,” when Jesus goes into the temple and kicks out the merchants, because they’re making a business out of faith. Here, everyone is trying to use the situation that the church is going through to gain support for themselves.

But in execution, can you actually imagine being there in front of everyone? [Laughs] I had just gone from shooting the scene with Ralph Fiennes out on the patio where we talked about the turtles. That was one on one, but now I was in front of everyone. Ralph, Stanley, John, Sergio — everyone was listening to me.

The night before, I really freaked out, and I asked John Lithgow for advice. From day one, he had told me, “I’m going to be your secret coach.” So I went to him and said, “OK, secret coach, I need your help, please.” He invited me over to his apartment to discuss it, and we talked about stage fright. He said, “Stage fright is always there, it’s just about how you manage it. You need to be empowered, and you have to know that when you deliver a speech, you own the scene. You control the pace. You set the tone. You determine your intonation, how you’re going to handle the emotional shifts, everything. Nobody is going to cut you off, or tackle you, or call a direction. They’re going to let you run this whole scene from beginning to end. And once you’re done, you’ll get some direction, you’ll try to incorporate it, and you’ll do it over again. But every single time, you own the scene.”

Did that translate on the day of?

One of the things that my first coach ever told us is, “Everyone Is cheering for you, because everybody wants you to do your best.” That’s how it felt that day. But still, when we were about to shoot that scene, I had the microphone here [on my chest], and Edward Berger comes close to me, and says, “Are you OK? Do you need anything?” I told him I was fine, and he says, “I can hear your heartbeat.” I had no idea, but I told him, “Well, if the heartbeat is coming through in the sound, maybe it would be a good idea to keep it in the background, because it’s a very heartfelt speech, right?” I have no idea if they used it, but it was fun to know that he could hear it.

You and the rest of the cast have been getting rave reviews for your performances, what’s up next for you?

There are a few shows of interest that my agent and I are looking at but can’t talk about yet. I just hope that this experience will lead to even more interesting, challenging experiences. That’s all I can hope for at this point. It’s been overwhelming the big reception that this has had, but it’s very encouraging, and I’ll keep running with that.

Cat Cardenas is a Latina writer and photographer based in Austin, Texas. Her work has appeared in Rolling Stone, New York Magazine, Harper’s Bazaar, GQ and other publications.