There was a time when David Oyelowo saw method acting as a bit on the pretentious side. Which is saying something, coming from a drama school graduate and sometime Shakespearean actor. But when he landed the role of Peter Snowden in Nightingale, an unnerving one-man drama which premieres May 29 at 9 p.m. on HBO, he realized he simply hadn’t yet played a character that demanded that kind of immersion.
It only take a few minutes watching Oyelowo onscreen to understand why this role is the one that changed his mind on going method. Peter Snowden is a veteran living with skeletons—literally—in his closet. After revealing his transgression to a webcam in the opening scene, he begins to unravel psychologically. Oyelowo moves Peter through the stages of his breakdown with no other actors on a set that consists of a handful of rooms in a modest house.
Nightingale is a major departure from the role that garnered Oyelowo accolades earlier this year, when he played Martin Luther King, Jr. in Ava DuVernay’s Selma. On the day of Nightingale’s premiere, Oyelowo spoke to TIME about inhabiting a character like Peter, how his wife felt about sharing a bed with Dr. King and his formula for a long career in Hollywood.
TIME: What was your reaction when you first read the script?
David Oyelowo: It was complete surprise that someone had been as brave and inventive as the script demonstrated. [It’s] one guy in a house, who starts out by doing something unthinkable, and we are asking the audience to stay with him for nearly 90 minutes. Frederick Mensch, the screenwriter, was breaking a lot of rules, but in a way that still felt compelling, showing a character the likes of which I personally hadn’t read and even seen.
And you went method for this role, correct?
I did. In the past, the notion of method has felt a little on the pretentious side, a little self-indulgent. I had done films like The Last King of Scotland and Lincoln, in which both Forest Whitaker and Daniel Day Lewis, respectively, had employed that technique, and I think everyone will agree the results are undeniable. But for me, a role hadn’t come along that warranted that. The main reason I did it is that I didn’t know how to play someone who is so in their own head, so adept at creating a world within which they can survive in order to deal with what they’ve done. If ever there was a role that you would want to make that choice with, it was Peter Snowden.
What does it feel like to wake up and go to bed every day as this person who’s not you?
In employing it both in Nightingale and then eventually with Selma, which we ended up shooting after Nightingale—and I don’t think I would have employed it [in Selma] if I hadn’t experienced its benefits doing Nightingale—the idea is to put yourself to the side enough whereby you are in the habitual mental, emotional and spiritual state of the character, so that when the cameras roll you are closer to the truth. You are making choices that the character would make because you are developing a muscle memory as to how they behave.
Did you see your family during the shoot?
Anyone who sees the film will agree that that’s not a human being you want around four young children and a lovely wife. Thankfully it was only three weeks because I’m never apart from my family for more than two weeks. Around about the 13th or 14th day I snuck back to see my family for half a day. Admittedly, it was a bit of a weird experience, because they are with somebody who looks like daddy, sounds like daddy, but daddy isn’t all there.
Is that fun for your kids or is it strange for them?
My kids are quite young—they’re 13, 10, 7 and 3—and they’ve lived a lot of their lives on movie sets. It’s their normal, in a sense. It was weirder for my wife, I think, who felt while we were doing Selma like she was having an affair with Dr. King.
Did you study performances by other actors for this role?
[I tried to find] other films like this, where it’s just one person in a very confined location, and I struggled. There are films like Castaway, that focus on one character but they do have interactions with other characters. At some point my search stopped because I realized this is something singular and I should embrace that. Since doing the film I did see Tom Hardy in Locke, and that’s the film that I think is most in the same hemisphere.
There’s a lot of ambiguity in Peter. Did you find it necessary to fill in some of the gaps of his backstory?
You can’t afford for there to be gaps in your pool of knowledge when it comes to a character, otherwise what ends up onscreen is generalized and unspecific. Whether the audience knows where he went to high school or not, it’s something you have to have a notion of because it all works itself into the truthfulness of a portrayal. I spent time with a psychiatrist asking if he had met people like Peter, and he had. They tended to be people who have associative identity disorder, what used to be called multiple personality disorder, where you establish different versions of yourself in order to deal with trauma. Once I locked in on that, I was able to pinpoint that there were about seven different versions of Peter, and that enabled me to be more specific in a given situation.
Given that a lot of people got to know you as Dr. King, how important was it to take on a role that was very different?
Hugely important for me. Nightingale is the kind of film that could, and often does, slip beneath the radar. We were not anticipating the platform that HBO has so wonderfully given the film. So it’s absolutely what I look for in the characters I play, not just for me, but for the audience. I believe the path to a long career is to keep the audience guessing. Daniel Day Lewis is my absolute hero from that point of view. I literally will pay to see anything he does because I know it’s going to be something different than I have already seen. That’s exactly the kind of career I would like to emulate.