Several things “haunted” the director while working on the adaptation, but one scene was particularly scary to get right

When it came to making Wicked, Jon M. Chu had more than a few fears.

Following a recent screening of the box-office hit — an adaptation of Stephen Schwartz’s iconic Broadway musical, which was based on Gregory Maguire’s novel Wicked: The Life and Times of the Wicked Witch of the West — the director, 45, opened up about the things that intimidated him in bringing it to life on the big screen.

Speaking alongside the film’s stars, Ariana Grande and Cynthia Erivo, as well as producer Marc Platt, at Hollywood’s Linwood Dunn Theater on Dec. 13, Chu revealed that he was scared of “everything” going into making the epic musical.

“I mean, everything scared me every day,” the director said, before citing one scene — perhaps the musical’s most impactful one — as the most intimidating of all.

Cynthia Erivo, Ariana Grande and Jon M. Chu on the set of ‘Wicked’.Giles Keyte/Universal Pictures

“‘Defying Gravity’ scared the s— out of me,” he revealed. “How are we going to have [Erivo as Elphaba] fly and buy into that and feel the truth of those words that Stephen Schwartz and [screenwriter] Winnie Holzman so brilliantly put into this 20-something years ago? How do we stay and how do we top ‘Popular’ on the show that is so iconic already?”

Despite this immense pressure he felt, however, Chu said that he eventually had to let his fears fade into the background.

“These things haunted us, but there [was] a certain point where we say worry is a misuse of imagination that we couldn’t worry at a certain point,” he explained. “We knew it was in our hearts.”

Plus, he added, the cast and crew — from its leading actors to the editor and cinematographer — are “all fans of the show” and “waited 20 years to see this movie by somebody.”

Cynthia Erivo is Elphaba in ‘Wicked’.Universal Pictures

Every day that they worked on Wicked, Chu said, the team put their “energy” into asking questions like, “How do you make a world that in context may seem like a dream, but how do you make it feel like a real landscape with real culture?”

“And how do you find that these two women have a real relationship that they both desperately want to be loved?” he said, adding that even when Elphaba “seems like she doesn’t look like she wants love,” Glinda “knows that that’s exactly what she wants.”

Every single day, Chu reiterated, “We talked about these things and kicked the tires over and over and over again. So it was just about every day: How can we push ourselves just a little bit more to get there?”

Also adding to the pressure was the fact that Wicked, and more specifically its source material, holds a special place in the American canon — a notion Chu recently discussed during a podcast appearance.

Cynthia Erivo, Jon M. Chu and Ariana Granda on the set of ‘Wicked’.Giles Keyte/Universal Pictures

The original story, L. Frank Baum’s 1900 children’s novel The Wonderful Wizard of Oz, is “so embedded in our culture and how we see story, how we see ourselves,” Chu explained while speaking with Jenna Bush Hager on her podcast, Open Book with Jenna, last month.

The author “always said that he wanted to be an American fairy tale with American dynamics to it,” Chu added, “which is like self reliance, optimism and resilience.”

Chu also noted that the iconic 1939 film adaptation of the book, The Wizard of Oz, became “a part of that fabric of what we look towards.”

“What’s beyond that rainbow became the image of what the American dream talks about,” the director said. “And so I think when we revisit that world, it’s like Oz is like our old friend that we’ve known for so long, but never actually looked at.”

Wicked is now playing in theaters. It recently was awarded best film by the National Board of Review.