When actors Katie Lowes and Adam Shapiro got the call that they would be the next Dawn and Ogie in Waitress on Broadway, making their Broadway debuts as onstage love interests, they had one thought: “Oh no.”

“We got cast and we were like f—,” says Lowes, best known as one of the citizens of Shondaland by way of Scandal. “I was like, ‘I’m screwed. I don’t know if I can physically do this.”

“Like we’d given them the wrong impression [with our audition tapes],” interjects Shapiro, who has made a name for himself on series like Sense8 andThe Affair and films like Steve Jobs. “We tried 6,000 times on the tape and we sent them the best version.”

To rewind: It took a lot to get them to make those tapes in the first place. Their dear friend, who just happens to be Waitress’ Tony-nominated composer-lyricist Sara Bareilles, casually texted them asking if they’d want to audition.

While they consider Bareilles a “genius,” Shapiro and Lowes thought her casting in this instance was anything but.

“We were not right for it at all. I had [my agent] call casting,” Lowes explains. “I said, ‘I can’t sing that song. That song isn’t my range. It’s on my break. I’m not a high belter. I know the show, I don’t even speak like that. I felt good about myself that I didn’t waste anybody’s time, including my own.”

But try saying no to Sara Bareilles. “Sara called us and refused our refusal,” says Shapiro.

Sitting down with the duo over pre-show snacks, Shapiro comes across with lightheartedness and earnestness (and the kinetic energy)—a sense of warmth and optimism with a goofy un-self-consciousness. Lowes is a force—steadfast, sure, willful, and focused. Her strength is the kind that encourages those around her to be exactly who they are. Together their exuberance is contagious; you can’t help but love them. And maybe that’s what Bareilles knew she needed in her next Dawn and Ogie.

Bareilles insisted that they make tapes. Dutifully, they did; and they nailed it.

Still, it did little to assuage the couple’s nerves. “Anyone can sing a song one time, that’s the thing,” Shapiro says. “It’s the eight times a week.”

And Shapiro and Lowes know about eight times a week. While Waitress may mark each of their Broadway debuts, Lowes and Shapiro are actually the theatre kids next door.

“My house was a total Broadway house,” says Shapiro. “My mom sat me down and was like, ‘You have to listen to Les Miz, you have to listen to Phantom, and you have to listen to Cats.’”

The daughter of a fashion photographer and a woman who studied dance, Lowes nurtured a love of song and movement and intimate musicals. “I was a big Sondheim…Cabaret [fan]…a little more racy and modern musicals,” says Lowes. “He’s a little more Streisand,” but both grew up musical theatre junkies. “I remember walking into junior high and seeing a play and realizing that shows existed that didn’t have music and dance and having my mind rocked,” Lowes confesses.

She eventually found herself drawn to drama, studied acting at New York University Tisch School of the Arts, and planned for a life onstage; he studied theatre at the University of Maryland and found his tribe during a summer in Hollywood, aiming for the screen.

After graduation, Lowes struggled to make ends meet as a one-line ensemblist covering all of the leads Off-Broadway while simultaneously waitressing. So she moved to the opposite coast. “When I moved to L.A. it was like, ‘You are dead to us, you have crossed theatre off your list, you are now a shitty television actor,’” Lowes recalls.

Yet even as she was working to break onto the screen, Lowes devotion to theatre never waned. Meanwhile, Shapiro admittedly coasted by booking the requisite number of national TV spots to pay his rent—until he met Lowes. “She was this tornado,” he says with a smile.

“I was this super Type-A, ‘We need to be in ten acting classes and we have to create an acting theatre company and we have to put them on ourselves and produce them ourselves and do the lighting board ourselves and then we have to sell tickets and we have to get agents there that we know,'” Lowes exhales. “I was such a hustler.”

Swept up in this woman’s dervish of passion and will, he, Lowes, and six other theatre friends built IAMA Theatre Company. “It made me feel like my artistic soul wasn’t dying in television land,” says Lowes.

Even surrounded by theatre and drama, in addition to their parallel success on some of Hollywood’s most coveted back lots, Lowes and Shapiro’s yearned for musical theatre. Which is perhaps why, the refused their friend’s offer to fasttrack to Broadway.

“I was so insecure about being the visiting TV person that doesn’t deserve to be here and isn’t good enough to be here,” says Shapiro.

“These Broadway singers and actors that we’re so lucky to be friends with are literally the Olympic athletes of acting,” says Lowes. “Every night when I’m done with ‘Opening Up’—I’ve done the show 80 times now—I’m out of breath.”

“When you’re in a scene in a movie and the scene is the three of us sitting at this table talking, I’m not even standing up!” Shapiro exclaims. “But in this show, within the first ten minutes of being in the show I jump over a chair, I trip over a napkin, I sing a full solo.

The duo rehearsed for a mere eight days before being shot out of a cannon and opening July 17. “By the numbers I was ready, but acting choices and confidence and comfort, no,” says Lowes who calls her Broadway experience “one big panic attack.”

But their collective anxiety only speaks to their sense of duty to honor the roles and Waitress.

“I feel three massive responsibilities with this job,” Lowes says. “One, when you’re hired by someone like Sara Bareilles—who’s your friend—you feel so lucky and honored to say her words; I also feel this responsibility to a lot of people who relate to this song ['When He Sees Me'] When I got outside every night to the autograph line, the women in the audience and the girls in the audience that might be teenagers or 20s, 30s, 40s, they come up to be and say Dawn’s song is the song I most relate to. And last, I’m playing Adrienne Shelley’s role in the freaking movie.”

Dawn may have started on screen played by the film's writer-director, but Lowes makes it her own, as does Shapiro with Ogie. “For the first few weeks, I was doing everything [original Ogie] Chris [Fitzgerald] did. Then a few weeks later a Chris thing would go and an Adam thing would come in and now people think Ogie was written for me,” he says. “I’m like, ‘You guys have no idea, you have to go back and watch Chris Fitzgerald because it’s his role.’ I’m just keeping it alive.”

But more than their own bents on the beloved characters, Lowes and Shapiro combine their own couple quirks and love for each other in a recipe for a singular onstage chemistry.

They’ve risen to the challenge they thought was ill-advised.

“I keep thinking about what I’m going to say [on our closing night] and I really truly believe this is the f*cking hardest professional thing I have ever done,” says Lowes.

“If there’s one thing I’ve learned as an actor through this process,” says Shapiro. “It’s to not be so afraid of things because I’m a terrible casting director for myself.”

Bareilles knew it: Casting the duo was a pretty good bad idea.