Two strangers meet and fall in love over the course of a New York City day in Nicola Yoon’s 2016 novel The Sun Is Also a Star (Delacorte). A Warner Bros. film adaptation of Yoon’s story opens in theaters on May 16, directed by Ry Russo-Young and starring Yara Shahidi (Black-ish) and Charles Melton (Riverdale).

In Yoon’s whirlwind romance, two teens find solace through one another, despite their dramatically different circumstances. Natasha (played by Shahidi), a budding scientist, has lived in Brooklyn for 10 years, but her family is now facing immediate deportation back to Jamaica. Daniel Bae (played by Melton) is an exchange student with a poetic sensibility. Their chance encounter leads to a day of exploration, introspection, and unexpected synergy.

Having a novel adapted into a movie is a rare accomplishment for any author, and many books optioned for film never get the green light. In Yoon’s case, lightning has struck twice: her 2015 debut novel, Everything, Everything (Delacorte) was adapted to the screen in 2017. The last couple of years, Yoon told PW, have been life-changing. “It feels surreal and wonderful at the same time. Five years ago, I spent my days at a job that absolutely sucked the soul from my body. Back then I would never have believed that I’d get my dream of becoming a working writer and that there would be movie versions of my books. It’s just wild.”

As was the case with Everything, Everything, Yoon contributed ideas, script notes, and general input on the film. She also had the chance to see the filming first-hand: “My husband, my little girl, and I spent a lot of time on set. We even filmed a cameo that I really hope makes the final cut!” Yoon will also walk the red carpet along with the stars for the film’s premiere on May 13 at the Pacific Theatres at The Grove in Los Angeles.

It was important to Yoon that the film capture the central themes of the book, which explores “the ways in which we are all connected and the ways in which people across all walks of life have much more in common than they think they do.” Daniel and Natasha, who meet at a critical juncture in their lives, take the time to “notice how our lives are influenced by everyone around us, even strangers.”

Wendy Loggia, senior executive editor at Delacorte, saw cinematic potential for The Sun Is Also a Star early on, as did fans: “Since its publication, readers have been asking to see Natasha and Daniel’s love story play out on the big screen,” she said. “I think it’s because The Sun Is Also a Star is not only about a romantic connection between two people, but touches on coincidence and fate, ideas that are eternally fascinating to us.”

The story is also a very New York one. “If New York City is the city that never sleeps, it’s also the place where you could, conceivably, fall in love in just one day—if not with a poet like Daniel or a pragmatist like Natasha, then with a beautiful work of art at MoMA, the melody of a busker at Union Square, or the best slice of pizza you’ve ever had,” Loggia said.

Film buzz also has sparked further interest in the book. According to Loggia, there has been a 50% increase in sales since the trailer went live in early February. Between Yoon’s Everything, Everything and The Sun Is Also a Star, the books have sold a combined two million copies. A movie tie-in edition for The Sun Is Also a Star is also now available to readers picking the book up for the first time or looking to reread it before seeing the film.

And for Yoon, when she’s not walking the red carpet, she’s at work on a new project—albeit, one that is still under wraps. “I’m working on my third YA book and something super-secret that I can’t talk about except to say that I can’t talk about it,” Yoon said.