There’s a brief moment in a recent Eternals featurette where a little boy named Jack (Esai Daniel Cross) excitedly tells his father, an Eternal named Phastos (Brian Tyree Henry) that fellow Eternal Ikaris (Richard Madden) is Superman. Jack’s not silly for thinking such a thing, Ikaris and Superman have some things in common, like the ability to fly and shoot lasers from their eyes. Yet Ikaris points out one crucial difference between him and the most famous superhero of them all—unlike Superman, he doesn’t wear a cape. It’s a cute moment, and for most folks, you might not think too deeply about the reference.

For comics fans, however, specifically for those steeped in both the Marvel and DC Comics canon, this crossover mention was a big deal. As Variety reports, not only did the moment launch a slew of “deep-dive reaction videos” and tweets, but director Chloé Zhao herself has even weighed in to set the record straight. Here’s the moment in question:

So why is a little boy mentioning Superman in a Marvel movie so wild? For starters, Superman exists in the DC Comics world, the biggest competitor to Marvel, and the guiding principle between the two massively popular comic worlds is never the twain shall meet. Marvel’s universe has Iron Man, Captain America, Black Panther, Black Widow, etcetera. DC’s universe has Superman, Batman, Wonder Woman, Aquaman, and more. So how and why was Zhao able to drop a Superman reference into the middle of her Marvel epic?

The Oscar-winning director told Variety that she takes full responsibility for this bold melding of the two major comic houses. The script, which she co-wrote with Ryan Firpo, Kaz Firpo, and Patrick Burleigh included the Superman reference, and it didn’t get any pushback from Marvel Studios chief Kevin Feige.

“You write it on the page, show it to Kevin, if he doesn’t say anything, that’s a go,” Zhao told Variety. “I don’t think there was a conversation. Not really, except, he goes, ‘Oh, that’s cool.’”

The reason Superman was written into the script, however, is much more thoughtful than simply getting away with a bit of superhero mischief. The main characters in Eternals are positioned as the oldest superheroes of them all, having been embedded on Earth since the beginning of human civilization. The Eternals have been quietly shaping human advancement, and, intriguingly, inspiring humanity’s oldest myths. Therefore, Eternals like Angelina Jolie’s Thena inspired the Greek goddess Athena and Don Lee’s Gilgamesh inspired one of the most ancient stories of all, the “Epic of Gilgamesh.” While Richard Madden’s Ikaris must have inspired the Greek god Icarus, his abilities also could have inspired the creation of Superman himself.

“We’re playing on a genre that draws so much from mythology, and Superman, for example, was created in the comics and also by these brilliant filmmakers along the way — they’re modern reinterpretations of mythical characters that exist in different cultures,” Zhao told Variety. “Ikaris is our interpretation of it. It doesn’t mean we can’t pay tribute to the really iconic version that we’ve all grown to love and has influenced us.”

There’s another iconic DC character who gets a shout-out later in the film, but, we’ll leave that one be. For now, just enjoy this brief moment of Zen, when those two competitors, Marvel and DC, can coexist in the same universe.

Eternals hits theaters on November 5.

For more stories on Eternals, check these out:

New “Eternals” Featurette Introduces 10 New Marvel Superheroes

First Reactions to “Eternals” Say Chloé Zhao’s Epic is an MCU Game-Changer

“Eternals” Featurette Boasts Stunning New Footage & Promises MCU-Changing Epic

New “Eternals” Footage Reveals Epic Battle Between Immortal Beings

New “Eternals” Images Reveal the Deviants

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New “Eternals” Images Tease Marvel’s Most Expansive Film Ever