Iron Man was the MCU’s first hero, but he’s not the franchise’s greatest. Neither is Captain America, Hulk, Thor, Carol Danvers, Doctor Strange, or any other Avenger. That title belongs to the rat that freed Scott Lang from the Quantum Realm in Avengers: Endgame. Without that roving rodent, Scott Lang would never have been able to get out of the Quantum Realm and Earth’s mightiest heroes never would have reversed Thanos’ Snap. But there’s a lot more to that microscopic universe, the Quantum Realm, than just time tunnels. It’s a small place full of big wonders and unimaginable possibilities. What are they? More importantly, what might they be? In short, what even is the MCU’s Quantum Realm? Before we learn even more of that subatomic realm’s secrets in Ant-Man and the Wasp: Quantumania, here’s everything we know (and think we know) about the MCU’s Quantum Realm.
The Microverse and the Origins of the Quantum Realm in Marvel Comics
Marvel Comics’ equivalent of the Quantum Realm is called the Microverse. Disney can’t use that term because Paramount owns the rights to the Microverse, along with its Micronauts, so instead, the MCU adopted the moniker “Quantum Realm.” The history of the Microverse is absolutely bonkers and worth exploring on its own, though. But what’s important for MCU fans to understand is that all Marvel microverses are wholly independent planes of existence unto themselves. From the Microverse Wikia page:
A Microverse is a dimension that can be reached from the Earth dimension by shrinking with Pym Particles and thus compressing the person’s matter to a certain point, thereby forcing it through an artificially created nexus into the other universe. The Microverses were once erroneously believed to exist within atoms. They are all described as parallel dimensions, rather than universes within universes.
Intuitively it seems like the Quantum Realm should exist as a part of our own dimension, the way microbes really exist in the world of humans. Instead, it’s one of the many dimensions that exist parallel next to our own, the same as other planes in the MCU’s Multiverse. When you go to the Microverse you aren’t just shrinking within our dimension, like a Russian doll of universes. You travel to a different one altogether.
The MCU’s Pym Particles and Going Subatomic Into the Quantum Realm
In the MCU, Hank Pym created his miraculous Pym Particles from subatomic, extra-dimensional particles. Until his unhinged protégé Darren Cross created his own equivalent, no other scientist came close to duplicating Pym Particles, which allows someone to either shrink or expand their physical body to extreme sizes.
Hank Pym also spent many years trying to harness the incredible power of quantum energy as part of his time studying the Quantum Realm. The microscopic dimension became an obsession of his following his wife Janet van Dyne’s disappearance. She went subatomic to stop a nuclear warhead without a way to reverse her shrinking process. Despite his attempts to find her, Hank was unable to learn much of anything about the Quantum Realm. He didn’t even know if it was possible for someone to survive there. That’s why he warned Scott Lang repeatedly about messing with regulator to avoid being lost forever in the Quantum Realm, a place where “all concepts of time and space become irrelevant.”
But Scott went subatomic to save his daughter Cassie and enter the Quantum Realm. As he shrunk he passed through smaller and smaller worlds, each beautiful and haunting in its own way. That included a mirror-like world similar to the dimension seen in Doctor Strange. When Scott finally stopped shrinking, he arrived in an empty, dark void dotted with only a few specks of light. If not for Cassie’s cries and the enlarging disc he carried, Scott never would have made it back to his full-sized own world. However, Scott didn’t initially remember anything from his trip to the Quantum Realm.
How Doctor Strange and the MCU’s Multiverse Connect to the Quantum Realm
The Quantum Realm is just one of the infinite dimensions beyond the Earthly plane the Avengers exist in. In Doctor Strange, the Ancient One told Steven Strange about how vast and varied the universe really is beyond the one humans experience. This is what she told him:
You think that this material universe is all there is? What is real? What mysteries lie beyond the reach of your senses? At the root of existence, mind and matter meet. Thoughts shape reality. This universe is only one of an infinite number. Worlds without end. Some benevolent and life-giving, others filled with malice and hunger. Dark places, where powers older than time lie. Ravenous, and waiting.
Is it possible Scott Lang traveled through some of these himself as he shrunk, especially the Mirror Dimension? It’s not clear, but what is important is understanding the MCU’s Multiverse, and therefore the Quantum Realm, is as much magical as it is scientific. Masters of the Mystic Arts’ sling rings make moving between dimensions possible. Hank’s Pym Particles allow non-sorcerers to travel through other dimensions as they journey to the Quantum Realm.
Ghost, Quantum Energy, and Connections Between Dimensions
Hank Pym and his daughter Hope van Dyne built a portal to reach the Quantum Realm in Ant-Man and the Wasp. Their Quantum Tunnel made it possible to send someone to a specific coordinate within the Quantum Realm. During the very brief moment they opened the tunnel in their lab, Scott had what he thought was a weird, vivid dream at his home. It was real, though. Janet van Dyne sent him a message across dimensions.
Scott’s previous brief journey to the subatomic world made him become “quantumly entangled” with Janet. Their minds shared a direct connection. Janet van Dyne had survived in the Quantum Realm for 30 years, and their quantum entanglement (a sort of telepathy across dimensions) was Janet’s way of planting a type of magical antenna in Scott’s brain. She used this to “speak” through Scott and share exactly when and where they could find her in the Quantum Realm.
Ava Starr (known as Ghost) almost ruined their rescue from the Quantum Realm. A tremendous amount of quantum energy hit a young Ava when her father’s own Quantum Tunnel exploded. (Notably, that explosion that looked a lot like Ego the Living Planet’s flowers growing in Guardians of the Galaxy, Vol. 2). That made Ghost quantumly unstable. “They call it ‘molecular disequilibrium,'” Ava said. “Every cell in my body is torn apart and stitched back together, over and over every day.” Ghost’s glitching in and out of the Earthly plane is also known as Quantum Phasing. That’s “when an object moves through different states of matter.” This chaotic state means Ava exists in “multiple parallel realities” at the same time.
Her condition makes her something less than tangible, which is why she can move through objects. However, with great focus, she can grab onto things briefly. At least long enough to punch and kick people. (Which she does with incredible force thanks to her body’s quantum energy.) Her S.H.I.E.L.D. suit also helps stabilize her powers so she can harness them and go from tangible to intangible when she needs to walk through walls or go invisible. Ultimately Ghost’s quantum displacement means she exists in both our dimension and the Quantum Realm and therefore doesn’t fully exist in either. To ease the tremendous pain her phasing causes at all times, Bill Foster built her a quantum chamber that releases quantum energy waves. That stabilizes her, but it’s only a temporary reprieve. And since Ava can only harness quantum energy involuntarily, a lack of it can kill her.
Foster’s plan was to fix Ava by stealing all of the quantum energy (via the tunnel) stored with Janet in the Quantum Realm. Hank was certain taking his wife’s quantum energy would kill her, though. He was right. But after much hullabaloo, Hank made it into the Quantum Realm via his tunnel.
Visiting the MCU’s Quantum Realm
Hank initially went to the same black void Scott ended up in. But then Dr. Pym shrunk even smaller (through yet another mirror world) into a surreal land of incredible color and life. It was as though Hank had traveled through a portal. We knew something about that place because Janet described it earlier when she spoke through Scott. “In the wasteland beyond the Quantum void, it’s very dangerous on the human mind,” she said. That gorgeous world, where Hank started phasing like Ghost until Janet stabilized him via touch, didn’t look like a wasteland. From a deleted scene, we know this place has intelligent life, “worlds upon worlds, entire civilizations,” including Easter eggs celebrating the comics’ Microverse cities.
Janet finally returned to the Earthly plane with 30 years worth of insight and connections into the Quantum Realm. Janet was able to feel Ava’s pain without touching her. Just as with Scott, Janet can connect with others via a quantum connection. She managed to transfer some of her own quantum energy to Ava, stabilizing Ghost. It instantly stopped Ava’s phasing and saved her life, though it wasn’t a permanent fix.
That’s why in an end-credits scene, Scott took another trip to the Quantum Realm to directly harness “quantum healing particles” with a specialized canister. The plan was to help save their “new friend,” Ghost. Unfortunately, that trip was not a snap like Scott expected. Right before Hope could bring him back, she, Hank, and Janet turned to dust. And Scott got stuck in the Quantum Realm. He just didn’t get stuck there for as long as it seemed.
The Rules of Existence and Time Vortexes
Time and space are so different in the MCU’s Quantum Realm that comprehending their true nature within that dimension might not be impossible. But we do know Janet van Dyne aged while she was there. Some rules of the Earthly plane, especially those regarding our bodies’ natural course, can seemingly still apply to humans there. We also know living in the Quantum Realm allowed Janet to evolve to the point she can pass quantum energy from her body to others just using her hands, even if she is still human. The more time a person spends in the MCU’s Quantum Realm the more powerful they become.
And yet, despite everything Janet taught us about this strange dimension, the most important lesson was one she didn’t tell us much about. As Scott was getting ready to dive into the Quantum Realm via the tunnel, Janet said, “Don’t get sucked into a time vortex; we won’t be able to save you.”
That way-too-casual warning indicated that within the MCU’s Quantum Realm, there are cosmic whirlpools of time that will suck you in. Someone can seemingly be lost in time forever there. (A time vortex would likely also stop a person from aging as Janet did.
Scott wouldn’t have just been lost in an infinite void of another dimension like Janet, either. No one would even know “when” he was lost. Even if he ever got out of a vortex, he could emerge at a totally different point in time. In the world of the MCU, just because you go into the Quantum Realm at one point in time doesn’t mean you’ll leave it at an equivalent point.
Avengers: Endgame and Using the Quantum Realm to Time Travel
After Thanos’ Snap, Scott Lang was only stuck in the Quantum Realm for five hours, not five years. That discrepancy was the key to understanding the Quantum Realm can also work as a time machine. Because “time works differently” there, you can enter the microscopic dimension at one point in history and come out at another. Either in the past or in the future.
Scott took his general idea to “navigate” and “control” the “chaos” of the Quantum Realm to the Avengers. After Bruce Banner’s failed attempt at sending Scott through time, Tony Stark returned to Avengers Complex to reveal he’d unlocked the key to time travel in the MCU. Yes, using the Quantum Realm, time travel is possible in the MCU. By using time tunnels in the Quantum Realm, the group was able to go back in time and collect the Infinity Stones needed to undo the Snap. That was possible because you can also pick up and transport objects through a tunnel, moving them from one point in time to another.
(Note: Unlike a kid’s baseball glove, the nature of Infinity Stones meant the Avengers had to return each one back to the exact point in time where they had removed it from. Failure to do so would have led to catastrophic splinters in the timeline. Clearly, you can mess around with time in the MCU, but time has its own rules. Rules that govern existence itself.)
Avengers: Endgame showed just how incredible the Quantum Realm really is. It’s a dimension of wonder and energy that makes time travel possible anywhere, everywhere, and at any time. But we know someone can seemingly get stuck there for an eternity, never aging or escaping. It seems like the exact place you would imprison your greatest enemies so they couldn’t destroy the entire multiverse as we know it. Of course, it’s also exactly the type of place you’d want to be if you were a man who never wanted to age so he could control everything. The type of place He Who Remains might have built his Citadel.
Is the Quantum Realm Linked to Kang, the TVA, and the Citadel at the End of Time?
Loki‘s first season provided major insight into how time works in the MCU, a place we know is made up of infinite universes stacked on one another. An Earth scientist in the 31st century discovered how to travel between parallel worlds. Eventually, so did his Variants. While many of them worked together, others sought to conquer all worlds. That resulted in all-out Multiversal War that threatened existence everywhere.
The original scientist, known to us as He Who Remains, ultimately defeated his Variants and won the war after he discovered the monster Alioth. Rifts in time and space caused by the war itself led to Alioth’s creation. He Who Remains then used the creature to guard his secret headquarters.
To make sure his Variants could never rise up again, He Who Remains created the TVA to oversee the Sacred Timeline he controlled. Represented as a circle, the Sacred Timeline holds together all the realities collected by He Who Remains after he won the war. The Sacred Timeline and TVA keeps him in charge and his Variants at bay. But that comes at a cost: free will.
Others people’s Variants within the Sacred Timeline can create an offshoot branch. If not pruned (i.e. killed), that Variant and its resulting branch threaten the entire timeline, which in turn could lead to the outbreak of yet another Multiversal War.
He Who Remains explained all of this to Loki and Sylvie at his Citadel at the End of Time, which itself is located past the Void where Alioth consumed condemned Variants. The Citadel exists outside of the Sacred Timeline, in a swirling world of blue and purple color that looks exactly like the Quantum Realm, a place where the normal rules of time don’t apply. But despite creating the TVA and living eons without aging, He Who Remains didn’t know everything.
Since time is a circle, everything that ever happened (or will ever happen) is always happening. But things can change within the circle when they happen again, as we saw when Sylvie killed He Who Remains. He thought his death would result in Multiversal War playing out exactly the same way, with him winning in the end. Instead, one of his Variants proved victorious this time, fundamentally changing the memories of the TVA’s workers. (Though not Loki’s, who was outside the Sacred Timeline when He Who Remains died.)
Even without all these obvious connections—both textually and visually—the Quantum Realm is the most logical location for the Citadel. It sits outside of time, and the Quantum Realm seems to exist outside of time. And since the Quantum Realm—with its own civilization—is where you would imprison an enemy who can threaten the Sacred Timeline for all infinity (like Kang the Conqueror), you’d want to be close by to keep him an eye on him and make sure he never escapes.
Especially since, as we saw with Janet van Dyne, the more time someone spends there the more powerful they become.
Only, He Who Remains is now dead, and one of his Variants his coming to take his place. A terrible Variant who will make pruning pesky Variants seem polite in comparison. How this Kang variant will escape from his prison, though, we still don’t know. For that, we’ll need to see Ant-Man and the Wasp: Quantumania. It’ll reveal even more secrets of the Quantum Realm, the MCU’s little dimension with big implications for the franchise.
Mikey Walsh is a staff writer at Nerdist. You can follow him on Twitter at @burgermike, and also anywhere someone is ranking the Targaryen kings.