The itty-bitty planning committee had a gargantuan task. When Marvel Studios decided to explore the subatomic Quantum Realm as the main backdrop for Ant-Man and The Wasp: Quantumania, director Peyton Reed urged his crew of designers to push themselves to devise the kind of unseen world that truly had never been seen. The Marvel Cinematic Universe has a long history of world building, which only made the job harder.

“It had to feel completely different, certainly within the MCU,” says Reed, who directed Bring It On,  as well as 2015’s Ant-Man and its 2018 sequel Ant-Man and The Wasp. “It had to feel different than outer space in Guardians of the Galaxy or Asgard in the Thor movies. It had to be its own thing.”

The previous movies about Paul Rudd and Evangeline Lilly’s miniaturized heroes found them shifting their size in our world, but this third outing ventures deep into the “micro-verse,” a dimension from the comics that exists far below the level of molecules and atoms, beneath photons, neutrons, and electrons, and even further beyond elemental particles like quarks and gluons. The Quantum Realm is a vibrant frontier of flora, fauna, and physics-defying landscapes, as well as a society of sentient beings fighting for control of it all. 

“A huge challenge on this movie was figuring out what it looks like,” Reed says. “And what are the laws of physics? And what’s the history of this? You get down there, and there’s all these different creatures and beings, and there are politics down there. And there’s oppression down there.” The oppression comes courtesy of Jonathan Majors’s Kang the Conqueror, a futuristic tyrant who has been exiled into the Quantum Realm for his brutal domination of other dimensions. Ant-Man and The Wasp are his chance to escape his microscopic prison and run roughshod over some bigger worlds.

To wrap his mind around the Quantum Realm, production designer Will Htay—who’d previously worked as a concept artist on The Force Awakens, Rogue One, and No Time to Die—proposed that it be a kind of liminal space full of portals and gateways. 

“Imagine a giant bubble filled with bubbles, but all the bubbles are moving, so they’re touching one another. Each one is a universe in itself, and they have connection points. There are holes going between them, but they're constantly moving,” Htay says, laughing at the absurdity of it. “I mean, you create this sort of crazy internal logic so that you could have these multiple worlds coexisting against one another, and time and space could be kind of folded in on itself. That was, conceptually, the kind of bonkers idea.”

To populate this place, Reed asked his team not to think small, but to think weird. The Quantum Realm is filled by beings who are cast-off from other places, so the storytellers reached into their own discard piles for inspiration. “Will Htay assembled this amazing group of conceptual artists, and with a guy named Andy Park—who is our Marvel art director—encouraged all those artists, ‘Open your portfolios and show us stuff that you’ve designed that maybe hasn’t found a place in any other thing,’” Reed recalls. “It can be the most whacked out idea. Let’s see if we can accommodate it storywise.”

That’s how they ended up with a menagerie of species who form the army that Ant-Man and The Wasp help lead in an uprising against Kang. “So one character would be presented kind of like steampunk. And this guy looks like a red glob,” Reed says. “It allowed us to create a wide and varied world.” The plot easily adjusted to embrace such a disparate mishmash. “The Freedom Fighters, who were opposing Kang, had to be this very disparate group of people who had lost their home worlds,” Reed says. “He’d conquered their people, and maybe they were the last survivors, and they’ve all banded together to resist.”

Reed credits prosthetics designer Conor O’Sullivan for building many of them around real actors. “He had to create all these different races of Freedom Fighters,” the director says. “These we call The Mystics,” Reed says. “They’re this very ornate sort of creature with almost kintsugi gold lines around their faces. They’re the sort of most religious sect of these Freedom Fighters. And we cast very tall people to play these characters. Once you got the headgear on, they were like seven and a half feet tall.”

Next to the Mystic on the left in the photo above is Veb, a rosy and bladder-like cephalopod (voiced by David Dastmalchian) who wobbles around producing a psychotropic ooze that, when consumed, allows beings who speak different languages to understand each other. Basically he’s a walking punchbowl. Think of him as Kool-Aid Man, but squishy—more likely to bounce off a wall than break through it.

To the right of Veb is Xolum, with the cranium that looks like a replacement fuse. “We liked the idea of this very fearsome warrior whose head is essentially a supernova, a star that’s got to be contained within this thick glass-like cylinder,” Reed explains. “When he unleashes it, it’s a lethal weapon.”

Finally, on the far right, is a member of a class of Freedom Fighters the production called the Steel Group. “They’re very mysterious warriors, and they’re black-clad with these black hoods, and they’re scary. They’re terrifying. You don’t see their faces,” Reed says. But pull back the cloaks and its a cuddle-fest. “We like the idea of the juxtaposition that they were cute, almost like Ewok-y kinds of characters.”

For all the wonders to be found in the Quantum Realm, it also lacks certain things: skies, for one. And flat horizons. Or anything that looks like it’s from our regular-sized world. “That was really tricky because how do you light these kind of internal spaces?” Htay says. The solution was found through the lenses of the world’s most powerful microscopes. 

“We looked at a lot of electro-microscopy,” Htay says. “We looked at all sorts of particle collisions. When they smash together subatomic particles, [these are] the kind of patterns that you get from that. There are recurring patterns that you see in nature as well, bifurcation and fractals. All of that sort of stuff became part of the language.”

In other words, the Quantum Realm is illuminated by bursts of energy and matter—storm clouds that radiate light and heat. “There’s an artist named Chris Parks who does these effects that aren’t digital, they’re actually chemical, and they’re literally shot in a Petri dish,” Reed says. “He did this whole shoot for us where, let’s say, you’ve got some yellow dye and you do these little droppers of blue and watch what the chemical reactions are, and we photograph them.”

As the chemicals and colors react to each other, the patterns that emerge almost seem to be alive. “They do take on a life of their own,” Reed says. “They’re all moving in a way that’s photochemical, so you could never predict how they’re going to move.”

Other light sources were the countless energy mines that the Quantum denizens work in to harvest their fuel. The glowing of these tunnels inside the distant looping walls of innerspace starts to resemble dim moons and suns that help light the world. 

“You see these kind of apertures, and depending on your relative scale and distance to them, sometimes they would look just like a very subtle curve, and other times they would look like a hole. And it just depended on where you were in relationship to that,” Htay says. Those effects were woven throughout the film where needed, creating a sky surrounded completely by land. Look up and you might see a forest, or a field, or a desert. “We really wanted to have the kind of curving horizon lines,” Htay says. "Where is up, where is down? You didn’t really know.”

That kind of dizzying effect is what puts the mania in Quantumania.