Never underestimate the power of divas working in tandem. When Cynthia Erivo and Ariana Grande sign on to a joint Zoom call, they deliver an elongated hiii so joyous it overpowers my laptop’s speakers and knocks the sound out temporarily. “It could have been that we were both screaming at the same time,” says Erivo. “Sorry, we came in hot,” Grande adds sweetly. “We were excited.”

Like theater geeks worldwide, they’ve waited more than 20 years for the Wicked musical to be adapted for the screen. Directors as varied as J.J. Abrams, Ryan Murphy, and Rob Marshall were all reported to have circled the movie at some point; rumor has it actors like Lea Michele and Amy Adams did too. For years, Stephen Daldry was attached to direct, but that version fell apart. Why did it all take so long? “Having done something well in one sandbox, there’s pressure if you’re going to do it in the other sandbox,” says producer Marc Platt, the engine behind both the Broadway production and the film. “Maybe subconsciously, I was like, ‘I’m not quite ready for that, emotionally.’ ”

A prequel to The Wizard of Oz based on Gregory Maguire’s novel, Wicked tells the story of Elphaba, the Wicked Witch of the West, and good witch Glinda before Dorothy, her house, and her little dog too landed in Oz. The Broadway show was staggering in scale and included two of this century’s most beloved musical theater songs, “Popular” and “Defying Gravity.” So the movie’s director would need a worthy vision. Enter Jon M. Chu, the man behind Crazy Rich Asians and In the Heights. Chu is an OG Wicked fan who saw the musical during its pre-Broadway tryout in San Francisco. “I remember thinking, Oh, wow. It feels like a movie already,” Chu says. Or maybe two movies, to give the story room to fly? Chu’s Wicked hits theaters this Thanksgiving, with part two arriving a year later.

Originally, Chu considered unknowns for the roles Kristin Chenoweth and Idina Menzel made legendary. Instead, the production landed on superstars. Grande playfully admits to “stalking” Platt to play Glinda: “It was literally 10 years of being like, ‘Knock, knock, any developments? Is there an audition coming this year, or next year? I would like to start preparing today.’ ” When the time came, she didn’t ease up. “Every time she came in to audition, she’d be there at least 30 minutes early,” says Chu. “I’d see her car circling. I’d be like, ‘Who is that?’ ‘That’s Ariana Grande.’ ‘Why is she here so early?’ ” Erivo had won an Emmy, a Grammy, and a Tony, but the Brit “honestly didn’t believe I’d be seen” for the role—and was one of the last people brought in for Elphaba. Once she got the call, she says, “I was training like I was a boxer.” After she sang, says Chu, “Marc and I looked at each other and we’re like, ‘We’re done.’ ”

You might assume that creating Oz would involve excessive CGI. You’d be mistaken. “I was like, ‘I want to do it the way I dreamed about it as a kid when I watched Hook,’ ” Chu says. “Behind the scenes, Steven Spielberg was on a dock with a giant pirate ship. I’m like, ‘If this is my one opportunity to do this, I want to do that.’ ” Wicked’s yellow brick road came complete with mud, and an actual train transports the witches to the Emerald City. And the singing? “These are live vocals,” Chu says. “When we were shooting it, those girls were like, ‘Fuck the pre-records. We’re going live.’ ” The director was skeptical. “There’s going to be a lot of wind in your air pipes. Is that okay?” he asked. They didn’t miss a beat: “ ‘Yeah. That’s what we do.’ ”

For “Defying Gravity,” Erivo actually sailed through the Western sky belting high F’s. “She had a harness pulling and pushing and yanking and tugging on every nook and cranny that there is,” says Grande. Her own numbers were no stroll in the park. “I’m literally never going to forget you jumping on a chandelier over my head whilst singing,” Erivo tells her costar. Grande giggles, remembering the stunt. “She was just so excited to perform for her new friend,” she says of Glinda. “She wanted to do a trick.”

Jeff Goldblum works more questionable miracles in the film as the so-called wonderful wizard of Oz. Bridgerton breakout Jonathan Bailey plays dreamy prince Fiyero, who drives a wedge between Elphaba and Glinda. And Ethan Slater, a Tony nominee for playing the lead in Broadway’s SpongeBob SquarePants musical, won the role of Boq with his comedic chops. As for Michelle Yeoh, she made sure Chu understood her limitations before casting her as the headmistress of Glinda and Elphaba’s school. The director remembers asking his Crazy Rich Asians star if she’d ever do a musical. “She’s like, ‘Jon, I can’t sing—but I would do anything for you.’ ”

The heart of Wicked is Elphaba and Glinda’s bond—a friendship between two women scrutinized by a less-than-forgiving public. “When two giant stars come together, you never know what kind of egos come flying out,” Chu admits. But Erivo and Grande forged a relationship that changed them for the better. “I just need to say that I don’t think people realize that she’s got the chops,” says Erivo, grasping Grande’s hand. “I don’t think people realize how brilliant this person’s brain and voice and talent is.” Grande turns away, her eyes welling up. She also paid Erivo a compliment, like the good witch she is: “She’s my favorite female voice. When I was watching you sing at the Oscars, I said, ‘I hope someday I get to sing with her.’ ” Thank goodness dreams come true.