The one-woman show, coming to Broadway, is the “Killing Eve” star’s first stage role. She dared herself to do it.Until last year, the actress Jodie Comer had never performed onstage. Comer, 30, a native of Liverpool, England, who began her career as a teenager, hadn’t gone to drama school. She hadn’t studied voice or movement. Her comfort was in the close-up, the medium shot. She knew how to make her face still and her voice quiet, and to let the camera do the rest. The theater directors she auditioned for didn’t trust that she could fill a stage.“It kind of felt unattainable,” she said.But she is filling one now. On Broadway, at the John Golden Theater on West 45th Street, her face is emblazoned above the marquee, twice. The art for the Olivier Award-winning “Prima Facie” — an intimate and harrowing monodrama about a woman contending with the fallout of a sexual assault — shows Comer bathed in pink tones, serene, in a barrister’s wig, her eyes closed; it also shows her washed in blue, screaming. Opening on April 23, the play, which Comer first performed in London last year, runs 100 minutes. She is alone onstage for all of them. It’s the theatrical equivalent of being shoved down a mountain the first time you put on skis, or off a high dive before you have even learned to swim.Comer put it a little differently. “I pushed myself,” she said.This was on a Sunday morning in late March, at an out-of-the way table at a West Village cafe. Comer, buoyed by the London-to-New York time change, had arrived early, chipper and casual in jeans and a fisherman’s sweater. (Casual, but not entirely anonymous: The reservation was in my name, yet a waiter had already brought a plate of complimentary pastries.) A plastic clip held her hair away from her face.About that face: Comer has wide-set eyes, full lips and an impossible milk-and-roses complexion. She looks like a Botticelli goddess who has stepped out of the canvas and into some cute ankle boots. And yet, if you have seen her previous work — the action comedy “Free Guy,” the action drama “The Last Duel,” the crusading BBC film “Help” and, most significantly, the queer assassin fever dream “Killing Eve” — you will know that her beauty is usually the least interesting thing about her. That prettiness is a mask she can remove at will, exposing something weirder, spikier, wilder beneath.A theatrical debut and an endurance test: Comer is alone onstage for the full 100-minute run of “Prima Facie.”Helen Murray“It’s like Jodie didn’t get the memo that she is staggeringly beautiful,” Shawn Levy, who directed “Free Guy,” told me. “Jodie is uninterested in relying on her physical appearance.”Unlike many beautiful actresses, Comer has mostly avoided wife, girlfriend and love-interest parts — and their inherent limitations. “From early on, my characters were quite nuanced or multifaceted,” she said. “I was probably very lucky that that’s where I started. Once people see you in that light, they latch on to that.”At the cafe, the morning sun showed her as friendly, unassuming almost, until she began to speak about her work. Then, behind those wide eyes, something like lightning flashed.“Jodie is extraordinarily powerful,” Shannon Murphy, a director who worked closely with her on “Killing Eve,” told me. “People aren’t just going to cast her as the girl next door. Because it’s a waste.”And yet, the role that Comer plays in “Prima Facie” is very much a girl next door, which lends the show much of its heartbreak and force. Written by Suzie Miller, an Australian attorney turned playwright, and directed by Justin Martin (“The Jungle”), also Australian, “Prima Facie” centers on Tessa Ensler, a promising barrister who has transcended her working-class origins and accent. When she finds herself the victim of a sexual assault, a crime whose accused perpetrators she had often defended, Tessa’s poise and selfhood collapse. In this play, the reality and violence of the assault is never in doubt. That it should happen to a woman like Comer’s Tessa — so pretty, so assertive, so canny — means that it could happen to anyone.“Prima Facie” debuted in Sydney in 2019, starring the Australian actress Sheridan Harbridge. When Miller and Martin knew that they wanted to take it to London, they began throwing around the names of English actresses. Martin suggested Comer. Miller said no. She had seen Comer on “Killing Eve,” as the mercurial assassin Villanelle, who is Russian-born and Russian-accented. Comer’s Emmy Award-winning command of the role was so absolute that Miller assumed that Comer was actually Russian. Once Martin gently corrected her, a script was sent.It reached Comer early in Britain’s lockdown, in Liverpool, where she was living with her parents. It spoke to her directly, and at volume. She had several friends who had undergone versions of Tessa’s experience. And the professional challenge was as serious as it was undeniable.“I was so fearful of it. I knew if I said no to it, it would be purely because of that,” Comer said. “But there was a part of myself deep down that believed I could do it, and I was interested in how I was going to get to that point.”That fear powered her initial approach to the role. “She gets scared,” Martin said. “But her way of dealing with it is to throw herself into it.”Comer as the assassin Villanelle with Sandra Oh in BBC’s “Killing Eve.” “People aren’t just going to cast her as the girl next door,” said Shannon Murphy, a director who worked closely with Comer on the show.BBC AmericaComer discovered theater in her teens. “I got into it because I enjoyed it. It made me happy. I don’t think that’s ever changed,” she said. A teacher put her forward for a radio drama, which led to an agent and to occasional television appearances. After graduation, she worked at a supermarket checkout and at a bar to make ends meet. Her idea of luxury was being able to make a living from acting only. Her first major break came seven years ago, when she was cast as the lead in “Thirteen,” a BBC drama about a woman who escapes from long captivity. Even then, Comer couldn’t land a stage role.But the recognition that “Killing Eve” brought changed all that. For Martin and for James Bierman, lead producer on “Prima Facie,” her lack of theater experience was never a problem. They offered her the resources — voice lessons, movement sessions — and the rehearsal time that she would need.Comer has always been an intuitive actor. The challenge, she found, was to take that intuition and extend it outward so that it reached the last row of the balcony. “Like, how do I emote from the top of my head to the tip of my toes?” she said.Rehearsals, which began early in 2022, were rigorous, as was Comer’s research. She spoke to barristers, to police officers, to a high-court judge. She visited a police station and attended a hearing. She had herself fitted for a wig. What would a woman like Tessa wear, she wanted to know. What would she eat? How would she sit, stand and speak? In watching some of the women barristers at work, Comer felt an immediate connection.“There were elements of it that felt like theater: the costumes, the cues, the rehearsal of the lines,” she said.The challenge in translating her instincts for TV acting, Comer found, was to extend them outward so that they reached the last row of the balcony. “Like, how do I emote from the top of my head to the tip of my toes?” she said.Sabrina Santiago for The New York TimesTelevision and film sets provide elaborate, realistic environments. Especially if the projects are shot on location. Theater is a more symbolic space, a conjuration of lights and plywood, which offered Comer a kind of freedom. In that glow, she could experiment, she could play. “What theater really sparked in me was that curiosity and sense of imagination,” she said with all the eagerness of a recent convert. Onstage there was no armor, no safety, no ability to stop and take it again, particularly in the scene in which Comer, alone on the floor of the stage, depicts the assault.Miller was convinced, even during rehearsals. “She is magnificent onstage; she’s a theater animal,” she said of Comer on a recent video call. “She’s the character. She’s there.”But after years of performing on television and film, Comer hadn’t known how a live audience would respond. Her anxiety remained up until the first curtain and perhaps even after. “I was actually quite consumed by fear,” she said. “I didn’t really come up for air.”She recalled that, toward the end of the first preview in London, she heard a woman in the orchestra crying. “It was the most guttural cry,” Comer said. “It spread around the theater. It was like the audience were giving each other this unspoken permission to feel whatever was coming up for them.”Stephen Graham, an actor who worked with a teenage Comer on “Good Cop” and then again on “Help,” saw “Prima Facie” in London and wept through it, admiring “the beauty and the subtlety and the nuance and the craftsmanship that went into that performance,” he said.I didn’t see it in London, but I watched it a few weeks ago, on video, via a National Theater Live performance capture. Her craftsmanship was apparent from the first few minutes. Look at Comer in a robe, I thought to myself. Look how good she is. Then the character seemed to take her over. Absorbed in the story, I forgot about Comer, forgot about her beauty, and thought only of Tessa.Miller had noticed this, too. “You don’t look at her and go, ‘There’s a beautiful woman crying.’ You go, ‘There’s a devastated woman crying,’” she said.Over breakfast, Comer had said that despite her leading lady facade, she understands herself as a character actress, someone who wants to disappear into a part, even though or especially because she can’t even disappear into a Village cafe. “I’d love to get to a point where I play a role where I don’t recognize myself,” she said.“Prima Facie” began as a personal challenge, a dare almost. Could she manage alone onstage for all that time? Could she pull off the scene changes and the radical shifts in emotion? But it has become about something more.Women waited for her at the stage door every night in London, telling her that their experiences mirrored Tessa’s or that they were considering careers in law to support women like her. By vanishing into Tessa, she has given these women a way to recognize themselves. That image near the marquee? It’s her face, doubly exposed, but it’s also a mosaic composed of photos of women who submitted their pictures and stories. That’s what Comer wants: to feel part of something bigger than herself, to feel some greater purpose is working through her.“It’s those moments where you step out of your way when you feel the most fulfilled,” she said. More