Jennifer Lee hustles down 8th Avenue in New York City at a breakneck pace, her eyes clear and sharp behind fashionable frames. Time is elusive, she says — it leaps away just when she thinks she’s caught up to it. 

As companions Robert Lopez and Kristen Anderson-Lopez nod in sympathy, Lee adds, “Every day, I’m thinking, ‘Where am I going? What am I doing? Don’t let me mess up.’”

“Don’t mess up” is an apt mantra for this trio behind the live-action version of “Frozen,” scheduled to open at the historic St. James Theatre on Broadway on Thursday. Jennifer wrote the book for the new show, and Robert and Kristen wrote the music and lyrics.

All three are fully aware of the burden of expectations that comes with “Frozen.” The musical is Disney Theatrical Productions’ biggest potential hit since “The Lion King,” which, after more than 20 years, is Broadway’s third longest-running show in history.

“I’m keeping my expectations low and my hopes high,” Kristen says as the group bundles into the basement-level dining room inside Joe Allen Restaurant a few days before previews.

“Frozen"has shaped their lives since 2012, when they first joined forces on the animated film, which Lee wrote and co-directed and for which Robert and Kristen penned the music. The project became a colossal blockbuster of unexpected proportions for Disney, winning an Oscar for animated feature, selling nearly $1.3 billion in tickets worldwide and becoming the domestic market’s highest-grossing movie with a female director at the helm — a distinction Lee held until Patty Jenkins’ “Wonder Woman” eclipsed her record.

Turning a bona-fide Disney franchise into a more nuanced Broadway musical proved a fresh challenge that the writers embraced with gusto.

Kristen makes a series of exaggerated emotional faces as she mimes typing furiously on a keyboard, pretending she’s the show’s lead characters. “I’m writing down what I would say, and I’m pretending and I’m feeling it and I’m writing it down,” she says breathlessly of her work ritual.

“I just think she’s gotten a really horrifying email,” jokes Robert, who is also her husband.

Lee bursts out laughing, plopping her spoon back in a bowl of split pea soup. Soon, everybody at the table is giggling like children.

Even within the context of their current nerve-wracking existence, this is no ordinary day.

A week later, Robert and Kristen will fly to Los Angeles to vie for their second Oscar, for the song “Remember Me” in Disney’s “Coco.” (They win.) They won their first Oscar for the earworm anthem “Let It Go,” from “Frozen.” The song has since earned a place in the timeless-show tune canon, having gone double platinum and selling more than 10.9 million copies in 2014 alone.

Lee is on her own roller coaster of an adventure as co-writer of her first live-action film, “A Wrinkle in Time,” Disney’s $100 million-plus bet on director Ava DuVernay and star Oprah Winfrey.

Robert says of the stage version of "Frozen," "Part of the challenge of this is that the songs people know, they know really well, and then there’s the vast majority of the score that they don’t know yet."

The “Frozen” movie soundtrack has what only can be described as a rabid fan base, with children, tweens, teens and adults belting out numbers in the shower and putting up countless covers on YouTube. There were seven songs in the film. The musical boasts almost three times as many, and because songs are the cornerstone of any successful musical, the execution of these numbers is of crucial importance. Their reception will make or break the show.

The writing process began in September 2015, and a first draft was due nine months later. They talk daily through every step of development, with bits and pieces of stream-of-consciousness monologues that Lee writes for the show’s two princesses, Elsa and Anna, inspiring lyrics for Kristen, and the music seeding ideas for dialogue in Lee.

As much as children love “Frozen,” the process of bringing the story to the stage required heavy-duty work boots.

“Those nine months that Bobby and I were in the basement expanding this into a big, emotional, lush musical, we took it as seriously as if we were adapting ‘War and Peace,’” says Kristen. “This was not looked as, ‘OK, now let’s just fluff it up.’”

“Adding, not padding. Deepening, not cheapening,” says Robert, repeating a phrase that Kristen coined during the process.

The idea was to plumb the depths of the story — about an ice queen who mistakenly casts her kingdom into perpetual winter and the plucky little sister who saves the day — for the messy, beating human heart within.

“We’re approaching the stage show as a singular piece of art,” says Lee. “For me, ‘Frozen’ wasn’t fully realized until this show. This is what it was made to be.”

Did you know?

Robert Lopez and Kristen Anderson-Lopez both developed musicals at the Eugene O'Neill Theater Center in Waterford. He worked on "Avenue Q" there in 2002, and she worked on "In Transit" in 2008.