Noah Jupe and Sadie Sink are playfully measuring their theatrical résumés. “Noah definitely has more Shakespeare under his belt than I do,” Sink says with a smile. “Oh yes, I’d say so,” Jupe replies. “How many lines did you have?” she presses. “Quite a lot, actually,” he answers. “More than 10!”

If Jupe wanted to boast, he could truthfully mention that he took on Hamlet at just 19. Two summers ago, he stood onstage in a replica of Shakespeare’s Globe and delivered “To be or not to be?” in Chloé Zhao’s Oscar-nominated adaptation of Hamnet.

Yet portraying an actor performing Hamlet was not rooted in long-held passion. “Honestly, Shakespeare just wasn’t something that grabbed me,” he admits. At school, the plays left him cold. “They were taught in such a dry, overly academic way that nothing stuck. There wasn’t any sense of excitement.”

Now, however, he is wrapping up a day of rehearsals for Romeo and Juliet, seated beside acclaimed director Robert Icke. Even he seems slightly surprised by the twist in his path. Sink – 23 and globally recognised as Max Mayfield from Stranger Things – starts to say she never imagined herself doing Shakespeare, then corrects herself: not this soon, at least. But after meeting Icke, she felt certain. “It was instinctive. I thought, ‘I have to do this. And I have to do it now.’”

Icke recalls telling her, “One opportunity that disappears quickly is Juliet. It’s an extraordinary role, and it only works if she’s truly young. Very few actors get that window.” As for why he wanted to return to the play, he feels there was more to explore.

His 2012 production – just his second professional outing – was praised for capturing the dizzy intensity of teenage love. Still, he looks back and thinks it wasn’t complete. “We were touring, working with almost no budget, and I was very young myself. With Shakespeare, you reach a point where you think you understand it, and then you spot the piece you missed and think, ‘Next time…’”

After meeting Sink and Jupe – whose screen work includes A Quiet Place and Honey Boy – he felt that moment had arrived. Five weeks of rehearsals have reshaped their understanding of the play. “When I think about our initial chemistry read, it’s wild,” Sink says. “We’ve both developed so much since then.”

For Jupe, taking on Romeo in the West End marks his stage debut, and he approaches it with open enthusiasm. “In film, you rarely get long speeches,” he says. “Here, you’re connecting your voice and the language directly to your heart. I haven’t experienced that much before. But when it clicks, it feels like you’re airborne.”

Sink’s background is different. A self-confessed theatre enthusiast, she made her Broadway debut as Annie at 10. By 14, she was filming Stranger Things, and the series defined much of her adolescence. Did it also shape her identity? “Of course,” she says. “It’s such a huge part of my life, and I’m grateful. It gave me stability and a kind of protection during those years.”

Though they had never met before being cast, they were familiar with each other’s careers. Both understand the unusual path of starting young. Sink’s family relocated from Texas to New Jersey so she and her brother could pursue professional acting. Jupe grew up around the industry, with a mother who acts and writes and a father involved in production. Their insight guided him, and now his younger brother Jacobi – who played the title role in Hamnet – is following suit.

“It’s not easy to go through that world and still love acting at the end of it,” Jupe reflects. “So meeting someone your age who’s had a similar experience is rare.” Sink nods. “When I turned 18, something shifted. I’m still passionate, but it means something different now. Everything before that feels like another chapter.”

She marked that shift by returning to the stage for the first time since she was 13 in John Proctor Is the Villain, Kimberly Belflower’s contemporary response to The Crucible. “It was the ideal project to come back with,” Sink says of the ensemble production, which ran for five months on Broadway. By the end, she knew theatre needed to remain central in her life. The play now transfers to London’s Royal Court Theatre, opening just days after Romeo and Juliet. Sink is also attached as an executive producer for its upcoming film adaptation.

Accepting Juliet did raise one concern. “She’s written as very young,” Sink says. “I wondered if I might feel too far removed from that stage of life.” Often described as mature beyond her years, she sits composed and observant as Jupe reflects on love, infatuation and the challenges of modern dating.

“We’re surrounded by dating apps and social media,” he says. “Even if you meet someone amazing, you’re aware there are endless other options out there. Exploring a relationship like Romeo and Juliet’s makes you hope that kind of intensity still exists.”

Sink raises an eyebrow. “They do both die.”

“True,” he concedes. “But acting on that initial spark feels rare now. Even when you think you’ve found something real, there’s this impulse to second-guess it.”

Icke finds that perspective intriguing. His earlier production highlighted how much of the tragedy hinges on timing and coincidence. “People frame it as Montagues versus Capulets,” he says, “but that’s not really the core. If Romeo arrives at the tomb five minutes later, Juliet wakes up and they live. It’s that fragile.”

He contrasts it with Shakespeare’s other tragedies. “In Hamlet, the father is already dead. In King Lear, the unraveling has begun. Here, disaster hasn’t yet taken hold. It could almost be a comedy.”

Revisiting the world’s most famous love story means convincing audiences to feel suspense despite knowing the outcome. Casting two young screen stars with devoted followings adds another dimension. Jupe’s recent awards appearances with his brother are just the beginning; upcoming projects place him alongside major film actors, as well as in the lead of a television adaptation of Sebastian Faulks’s Engleby.

Sink, meanwhile, has sparked widespread speculation with her undisclosed role in forthcoming Spider-Man and Avengers films, which she began filming in the UK last year.

Icke is acutely aware of how different his own life is from when he first directed the play. “I was 25 back then,” he says. “Now I’m a parent, which makes me far more sympathetic to the adults in this story.” As for what he’s picked up from his younger cast? “New vocabulary,” he laughs. Jupe teases him about learning the modern meaning of “hard.” “I had to check if that was positive,” Icke admits. “It is,” Jupe assures him.

“It’s a completely different world from when I was 20,” Icke reflects. “But if we do this well, younger audiences – especially those who might not usually come to the theatre – will be astonished by what they see.”

Romeo and Juliet runs at the Harold Pinter Theatre, London, from 18 March to 20 June.