After playing crime-fighting superhero Barry Allen on “The Flash” for nearly a decade, Grant Gustin has happily run away and joined the circus.

The Virginia-born actor can be found under the big top ― Broadway’s version of it, that is ― in the musical adaptation of “Water for Elephants,” which opened at New York’s Imperial Theatre last month. He stars as Jacob Jankowski, a veterinarian-in-training who is left destitute and adrift after a family tragedy in the early years of the Great Depression.

As recalled in flashback by an older Jacob (played by Gregg Edelman), the character flees town and becomes a train-hopping stowaway. He eventually takes refuge with the Benzini Brothers’ traveling circus, where he tends to animals and finds himself smitten with a horse trainer and acrobat, Marlena (Isabelle McCalla). The pair soon embark on a romance that becomes a high-wire act in its own right, given that Marlena is the wife of the circus’ volatile ringmaster, August (Paul Alexander Nolan).

“I’m drawn to characters who possess qualities I wish I had or could foster in myself a bit more,” Gustin told HuffPost. “The one comparison I can draw between Jacob and Barry Allen is their fight to move forward in the face of tragedy and great loss.”

Jacob “loses his parents, his home and his career path, and he really has nothing left, but he decides to find a way to keep living his life with light and optimism,” Gustin continued. “I tend to be pessimistic and hard on myself.”

“Water for Elephants,” directed by Jessica Stone and based on Sara Gruen’s beloved 2006 novel, marks Gustin’s Broadway debut. The actor is a charming and affable stage presence, performing the musical’s bluegrass- and folk-inflected songs (written by PigPen Theatre Co., a seven-musician collective) with aplomb.

And as it turns out, Gustin hasn’t left his superhero strength behind entirely. During one breathtaking sequence, the actor is hoisted in the air above the stage on a trapeze while singing.

“It was a little anxiety-inducing, for sure,” he said of the training regimen the scene required. “But all the safety precautions we can take have been taken, so it was more of a mental hurdle.”

Having previously showcased his vocal prowess as “evil Warbler” Sebastian Smythe on “Glee,” Gustin has had his sights set on Broadway for some time. His last stage experience was a 2010 touring production of “West Side Story,” in which he played Jets member Baby John. Over the years, he’d been offered replacement roles in a number of existing musicals, but was unable to commit to rehearsals given his rigorous shooting schedule on “The Flash.”

But after “Water for Elephants” completed its 2023 tryout run in Atlanta, and actor Ryan Vasquez exited the role of Jacob to join the company of Broadway’s “The Notebook,” Gustin was able to snag an audition.

“My dream has always been to originate a character on Broadway, and it had started to feel like it wasn’t possible,” he recalled. “There are a lot of talented people out there, so to get a chance to take a stab at something, it’s not easy. This opportunity fell into my lap, and I had to go fight for it and win it. I kind of became obsessed with getting the job.”

Though Gustin is usually based in Los Angeles, he’s hopeful “Water for Elephants” will be the first of many theatrical stints. He and his wife, physical therapist Andrea “LA” Thoma, will mark a personal milestone when they welcome their second child later this year. The couple also share a 2-year-old daughter, Juniper Grace Louise.

When it comes to navigating fatherhood and his career, Gustin plans to continue to seek “opportunities that I’m excited about” while “finding balance.”

“I’d never come to New York without my family, so it was a big conversation, whether we felt like we could do it or not,” he said. “My family’s my No. 1 priority, and they’ve been so supportive of me doing this. I tend to be more worried about how things will work out than my wife is. She takes the viewpoint of, ‘We’ll figure it out.’ I mean, she always reminds me to say positive things out loud.”

As for his future on Broadway, Gustin lists director Michael Arden ― who won a Tony for the Ben Platt-led revival of “Parade” last year ― as one of his dream collaborators, along with “Dear Evan Hansen” and “La La Land” composers Benj Pasek and Justin Paul. He’d also like to try his hand at a straight play, and he’s had conversations with playwright Rick Elice, who wrote the script of “Water for Elephants,” about working together on a second project.

“It’s good for me, both as a human and as an actor, to feel a little uncomfortable right now after getting so comfortable doing [‘The Flash’] for so long,” Gustin said. “I’d love to switch it up. I want to challenge myself in different ways ― maybe play some villains, some characters who aren’t easy to root for. I don’t know what the roles are yet, but I want to be able to do everything.”