[Editor's note: The following contains spoilers for In the Heights.]You’ve seen In the Heights in theaters or on HBO Max by now, right? If so, I’m willing to bet one of the many scenes you can’t stop thinking about is when Nina (Leslie Grace) and Benny (Corey Hawkins) sing “When the Sun Goes Down” while dancing on the side of a building.

Not only is it essentially the culmination of Nina and Benny’s story in the movie with the pair singing about their relationship and holding on to summer with Nina’s return to school right around the corner, but it’s also one of the film’s most dazzling set pieces. The song begins with Nina and Benny on the fire escape, but then launches into a dance performed with the building’s brick wall beneath their feet.

in-the-heights-corey-hawkins-warner-bros-social-featured
Image via Warner Bros.

While on Collider Ladies Night celebrating the film’s release, we spoke to Grace about exactly how they brought director Jon M. Chu's goals for the scene to screen. She began:

“We didn’t know for like half of shooting how that was gonna come together. We just kept seeing this vision that Jon kept showing us like, ‘Yeah, and then you guys are gonna dance on the side of the building. Yeah! And then you guys are gonna dance on the side of the building!’ We just kept being like, ‘Okay, but like …’ And he’s like, ‘No, there’s gonna be a wall. Don’t worry. They’re building it. They’re gonna build it. It’s gonna cost a lot of money, but we’re gonna make it happen and you guys are gonna dance on the side of the building off the fire escape.’ I was like, ‘How though? Like, how?’”

In the Heights Fire Escape Scene
Image via Warner Bros.

Eventually Grace and Hawkins did find out how and when that happened, they had to learn how to pull it off fairly quickly because the wall was finished fairly late in the game. She continued:

“No harnesses, all [choreography] done by us. We learned all the choreo in the last week, the week leading up to shooting it because the wall was only finished right in time for us to learn in one week what we needed to shoot on the day. We had rehearsed some things, but until you get onto the side of the building, onto the fire escape, you really don’t know what you’re working with and what’s gonna be needed.”

Grace went into further detail, highlighting the connection to Fred Astaire’s floor to ceiling dance in Royal Wedding:

“Everything on that side of the building was crafted for us to create those Fred Astaire and Ginger moments - when I’m sliding on the side, when Corey jumps up and pops off of the fire escape, and all those things. When we slide down as we do our kiss, there was something there which you don’t see - I’m giving away a little bit of the movie magic, but there were so many things that were happening technically in order to make that moment happen. And also I can’t even imagine cinematically what all the crew was doing. There was a huge crane, 360 green screen action. Shout out to the effects team.”

Leslie Grace and Corey Hawkins in In the Heights
Image via Warner Bros.

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Clearly there was a lot of movie magic necessary to make this scene happen. Given that Grace was right smack in the middle of it all, that has to mean the behind-the-scenes requirements can’t melt away for her like they do for us viewers while watching the finished film, right? Turns out, that’s not the case. Grace explained:

“So when I got to see it, I was just blown away because I thought that I would still be feeling all of the technical things we did to accomplish this illusion, but when I saw it, I forgot everything. I was fully transported. I keep saying it, but it was the truth. I was like, ‘How is this possible?’ You’re seeing the plane flying and you’re seeing the people crossing the street, and it was just incredible.”

If you’re looking to hear more from Grace, there's so much more from where this came from! You can catch her full uncut Collider Ladies Night conversation in podcast form below:

KEEP READING: Becky G's Reaction to Leslie Grace Scoring Her First Feature Role with 'In the Heights'