NEW YORK, NY.- On a morning in mid-August, a breeze stirred Central Park’s midsummer leaves. Children skipped, dogs lolloped, a bunny peeked out from a hedge near the Great Lawn while a nearby saxophone ruined “Isn’t She Lovely.” It was a very nice day to fall in love.

The actors Kit Connor and Rachel Zegler were there, hiking up to Belvedere Castle and then down to the Shakespeare Garden. Connor, 20, and Zegler, 23, don’t plan to fall in love. But the next day, at rehearsal, in Brooklyn they would discover how to make the characters they play fall desperately, terribly in love.

As the stars of the “Romeo + Juliet” that opens on Broadway on Oct. 24, they will die for love, they will die for each other, eight times a week. Both are making their Broadway debuts and both have the not exactly enviable task of making a 16th-century play with (apologies for centuries-old spoilers) a famously grim ending feel breath-catchingly new and vital.

Daunting? Not at all.

“It should be fun,” Connor said, not without some anxiety. Zegler gave him a sardonic look. “It will be fun,” he said.

Connor, a British star of the Netflix teen romance “Heartstopper,” and Zegler, an American who made a thrilling film debut in Steven Spielberg’s “West Side Story,” had never met until March, shortly after they each agreed to star in the revival, dreamed up by Tony-winning director Sam Gold, with music by Jack Antonoff. They had been offered the roles separately, without the benefit of a chemistry read. That spring day, Gold brought them to Circle in the Square Theater, where previews will start Sept. 26, then bought them cups of coffee at the Cosmic Diner.

Chemistry, Gold said, speaking now during a break rehearsal, is something a director can’t predict. “Man, if I could guess that, I’d be more successful than I am,” he said. “It’s hard. I have failed at that before.”

If Gold had failed again, if the March meeting had sputtered, they all might have gone their separate ways. “It was scary, when we first met,” Connor said. He recalled hurrying in a few minutes late. “When you’re meeting a romantic interest, you have to keep your fingers crossed because you just can’t fake it. And when you do the greatest love story of all time — ”

“Oh, yeah,” Zegler said, completing the sentence. “We should probably have chemistry.”

Happily they did. Gold recalled an immediate effervescence, a sparkle under the diner’s punishing lights. “They could have been scared, tentative, guarded,” Gold said. “But it just felt super easy.”

That was how it felt to Zegler and Connor, too — an instantaneous comfort, a liking. “On first meeting, I was like, oh, we’ll be fine,” Zegler said.

This ease was not a surprise to the actors who have played Connor’s and Zegler’s love interests in past projects.

Joe Locke, a “Heartstopper” co-star, praised Connor’s openness and vulnerability. “Kit made everything so easy,” he said, adding, “It’s hard not to fall in love with him,” clarifying that this love was friendly rather than romantic.

Tom Blyth, Zegler’s co-star in “The Hunger Games: The Ballad of Songbirds & Snakes,” described a similar connection. “It was very easy for us to portray love,” he said. “Rachel has an ingénue thing about her, but she’s not just an ingénue. She’s wise beyond her years.”

After their meet-cute at the diner, Zegler and Connor met again for a half day, in suburban New Jersey, to shoot a teaser trailer for the show, a moody music video, and then months later in London for a photo shoot, followed by a reading of the play. Gold joined them via a video chat, and he liked what he saw. “The two of them were off book, falling in love in this conference room,” he said. “It was as if they started floating above their chairs, it was so good.”

But competing movie shoots made any other hangouts impossible, so this morning, in Central Park, was their first chance to really get to know each other. Zegler had arrived early, as is her way, in matching Thom Browne separates and heeled loafers, which were not perhaps designed for the park’s more rustic paths. Connor, a few minutes late, was in wide-legged jeans and a white shirt, with ripped shoulders.

“Yeah, I ripped them myself,” Connor bantered. “On the way here. So nervous.” Then he kidded Zegler for her rabbit-shaped purse. “I find that quite alarming,” he said. “I don’t like it at all.”

“Don’t be weird,” Zegler said.

She had flown in the day before from Los Angeles; he’d arrived two days prior from London. He claimed not to feel jet lag. She did. She knew the park well, having often visited it when she was growing up in New Jersey. He’d been once and hadn’t cared for it — too curated, too crowded. They headed up to the castle, a fantastical former meteorology station. “It’s very Disney,” Connor said. “I love America.”

In the Shakespeare Garden, Connor pointed out Ophelia’s flowers. Zegler led them onto a path that accidentally trespassed on the construction site for the Delacorte Theater. Suddenly, a helicopter thwapped overhead.

“Kit, they know you’re here,” Zegler said.

“They follow me everywhere,” Connor fake-sighed.

Together, the actors seemed more like longtime friends than brand-new ones, with an energy more akin to big sister and little brother than star-crossed lovers. With luck and the hard work of rehearsal, that energy would change. They had some trepidation (Zegler: “I hope I don’t let him down”), but mostly they trusted the script, the process, each other.

“I can joke with you, which is nice,” Zegler said to Connor. “If I can’t joke with you, how are we going to fall in love every night to the point that makes us suicidal?”

“It’s really important that the two of us have trust and intimacy,” Connor added. “It’s nice that we have a level of safety.”

Safety was a good thing. Both were suffering from some degree of Shakespeare-induced impostor syndrome. “I’m not actually meant to be here,” Zegler said. “I am meant to be doing my high school production of ‘Shrek’ until I die.”

Connor, whose only previous flirtation with Shakespeare was an extremely minor part in the play within a play in “Hamlet,” felt the same. “You feel a sense of, ‘Am I cut out for this?’” Connor said. And in an intimate theater like Circle in the Square, which plays mostly in the round, there is nowhere for an actor to hide.

But that fear has an upside. It would give their performance a newness, a freshness. In casting the play, Gold had sought actors, he said, “who could make the audience feel the first-timeness of their love story. It’s really important that this feels like these are kids who have never experienced before, the things they’re experiencing.” (He joked that working with actors this young “is getting me out of my midlife crisis.”)

Of course, Zegler and Connor, have experienced these things before, in performance and in life. Maria of “West Side Story” is modeled on Juliet, and Lucy of “Ballad of Songbirds and Snakes” has a lot of the character in her too. Nick on “Heartstopper” is a version of a Romeo. And each is young enough to recall, vividly, the intensity of real first love.

“First love is rough,” Connor said.

“It’s like a rite of passage,” Zegler added.

“These feelings, they were world ending.”

“Really.”

They don’t expect to feel anything quite as intense in rehearsal or performance. If feelings do arise, each has an outlet — songwriting for her, poetry for him. (Locke had confirmed this: “He’s the most textbook Romeo. He writes poems, for God’s sake.”) And if their emotions overflow those containers, well, they can just put that into their performances.

“If you have a bit of spillover, save it for the next night,” Connor said.

“Spillover is good for the yearning,” said Zegler.

Connor misheard “yearning” as “urinating,” which provoked general laughter.

So for now, there was no spillover, no tragedy, no sorrow, sweet or sour — just a lot of affectionate ribbing, mostly from Zegler. When Connor mentioned a book he’d recently read, she lightly trolled him, “You read? Wow.” There was more teasing about his haircut and his shirt. Connor took it in good humor.

After the castle and the Shakespeare Garden and the trespassing, Zegler and Connor wended their way down to the Swedish Cottage Marionette Theater, clowning on the offered play, a puppet show about a cow. They were buoyant, breezy, ready to begin the work of falling in love. Maybe this time it would end well for Juliet and Romeo, they joked.

“Thank God we don’t die at the end,” Connor said.

“Thank God we have a happy ending,” said Zegler.

“That’s what sets our production aside,” Connor said.

This article originally appeared in The New York Times.