The Ending Of Moonfall Explained

More than any of the other disaster pictures in director Roland Emmerich's oeuvre, "Moonfall" is a film whose marketing centers around a mystery. Sure, audiences can expect plenty of CGI carnage, questionable use of scientific concepts, and everything else the helmer's particular brand of blockbuster has to offer. But it's the unsettling suspense surrounding the implied secrets of the moon that lend the film any real intrigue.

By the time the conclusion rolls around, we've seen a lot of devastation, parsed through a ton of exposition dumps, and marveled at the beauty and horror of space itself. It's the final act, however, and its many revelations that may leave some moviegoers trying to unpack the answers they so longed for. If you've just seen "Moonfall" and want some help digging through the insanity at the film's climax, we're here to help. 

But if you haven't seen it and are just dying to know what's going on from those omnipresent TV spots, we've also got you covered. What is inside the moon? Why is it hurtling towards Earth in the first place, other than it makes for a rad ticking time bomb in a big budget sci-fi flick? 

Well, it's a bit complicated, but that's why we're here. This is the ending of "Moonfall" explained. Spoilers to follow!

"Moonfall" begins when a routine space mission goes awry, with two astronauts, Brian Harper (Patrick Wilson) and Jo Fowler (Halle Berry), barely surviving what the former can only describe as an attack from an unidentified source, and the latter, having been unconscious, must assume was some kind of solar flare. The dispute leaves the colleagues and friends estranged, with Brian becoming a washed up deadbeat to his only son Sonny (Charlie Plummer) and Jo moving up the NASA ladder. 

Ten years later, a conspiracy theorist named K.C. (John Bradley) discovers that the moon has been knocked off its orbital path and is on a collision course with Earth. He winds up teaming with the two former friends to figure out how to correct the moon's course, but they both balk at his theory that the moon isn't what it seems.

They begin to grow more sympathetic to his crackpot theories when Jo is promoted to head of NASA and given clearance to see the original footage from her and Brian's botched mission. There, she meets a mysterious spook named Holdenfield (played by Donald Sutherland) who explains he's been responsible for covering up the truth about the moon since Earth's earliest expeditions. 

He goes full Deep Throat in "All The President's Men" while Jo witnesses, with her own eyes, the phenomena Brian tried to get her to believe, a heart-stopping swarm of black nano-machines moving with malice and sentience. She surmises that whatever this entity is, its presence is what set the moon out of alignment, and it will need to be dealt with if Earth is to be saved.

But even though NASA's upper echelon has been aware of the moon not being what it seemed for decades, and even though they have spent considerable energy and effort keeping that a secret, they don't know its true origins. They only know enough to know it's out of humanity's grasp — and that this knowledge becoming common would have catastrophic repercussions for society as a whole.

Initially, Jo had scrambled an emergency mission with the help of some European allies for exploratory reasons, the idea being to see what's inside the 26-kilometer deep crater on the moon that the black swarm had come out of. But that mission killed everyone involved, so Plan B had to be a little more drastic. With no faith or support from the rest of the government, and very little resources at their disposal for such a short notice set of circumstances, Jo has to bring in Brian, the only other person to encounter this entity, and K.C., whose status as a "megastructurist" might prove useful now that they know most of the accepted knowledge surrounding the moon is now completely useless.

The new plan is to get a lander onto the moon's surface equipped with a super-powerful EMP the military had been developing for years to deal with NASA's secret moon problem. The project had been abandoned as too costly a weapon, but one working prototype exists and must be used to destroy the black swarm entity. But as the moon's gravitational pull and exponential velocity increases, the ticking clock's time contracts and a number of setbacks make this plan untenable. The one usable rocket loses one of its engines. The moon itself begins to fall apart as it gets closer to our atmosphere, sending debris all across the landscape. 

But the gravity tsunami the moon brings with it proves enough to help get a rocket out of orbit even without the sufficient engine thrust necessary to properly launch. Unfortunately, this scientific revelation comes after everyone working for NASA has been released to go home and find shelter with their loved ones, leaving only the film's three leads to embark on this insane mission alone.

But this plan being a long shot means the military industrial complex is already hard at work at a much more logical solution to this absurd problem: they're going to nuke the moon. 

This adds extra pressure onto Jo and Brian's mission, as they're stranded out in space, unsure of whether their cowboy maneuvers will even work — and if they do, they have no way to communicate with the military to stop them from nuking the moon to smithereens. But Jo does have one contact on the inside, as her ex-husband Doug (Emi Ikwuakor) is with the Joint Chiefs in the Colorado doomsday bunker Jo was supposed to bring their son to.

Removed from the consortium of scientific theory Jo and Brian have access to, Doug is a straightforward guy who isn't exactly thrilled at the "nuke the moon" plan, but in the absence of better, more concrete plans, sees it as humanity's only chance to keep from having the moon hitting everyone's collective eyes like a big pizza pie. 

If only he had some way to know that his ex-wife's long shot plan of actually getting into space really worked...

Luckily, Brian's son Sonny, alongside Jo and Doug's young son and Jo's foreign exchange student Michelle (Kelly Hu), saw the rocket take off. They've been driving to the doomsday bunker themselves, running into all manner of peril. But Jo's son has a satellite phone with a direct line to his dad, so they're able to notify Doug that the mission is active and that if he pulls the trigger on launching all those nukes, he'll also be pulling the trigger on his son growing up without a mother. 

This leads to a standoff between Doug and every other authority figure in the bunker right at the moment they're meant to begin the launch sequence to initiate a nuclear onslaught on the moon. It's a crazy bit of drama, to be sure, because Doug doesn't understand any of the intricacy related to their plan, how far along they are, whether it's even still feasible. 

All he knows it that Jo has never let him down before.

But the plan is essentially screwed. Brian's initial idea is to lure the black swarm out by exploiting its reaction to electricity before destroying it with the EMP, but it sees through their original ruse. When it tries to destroy their ship, they realize it's not solely electricity that the swarm responds to, but rather organic matter alongside machinery. With no other recourse, Brian pilots the lander into the deep crater the swarm has retreated into, and that's where the real fun begins.

The inside of the moon is, as K.C. had theorized, a megastructure: an enormous vessel crafted by advanced alien life. He says some in his community believe that all megastructures are arks, but what they discover next proves he's only half right. As the swarm tries to destroy them, there is another opposing force within the moon's core, one that takes over the controls of the ship and guides them to safety on the other side of a blast door — an area, they discover, that has air. 

When K.C. and Jo wake from the crash, they discover Brian is missing and go exploring this newfound space. But Brian is already communing with an entity that possesses all the answers. It speaks to him in the guise of his son, but it's the operating system for the supermachine that is the moon. It is, in fact, a megastructure, but it wasn't created by aliens. It was made by humans.

As told to Brian, the moon is an ark created by a form of the human race that was far more advanced than ourselves. They had created an idyllic society, a literal utopia, and proliferated throughout the cosmos. But one day, the artificial intelligence they had created to help run this society grew sentient, turned on them, and vowed to destroy all of humanity. They created moons to find suitable places to build new planets to be seeded with human life. Thus, our Earth is the only successful settlement, created from the moon and seeded with human DNA. The moon orbits the Earth to protect it should the AI swarm ever find it, as it has now. 

The operating system tries to understand why Brian is so willing to risk his life to save the rest of the planet, and his answer — about love for his own son and for his race — lets the moon know he is ready to get back into the game and stop the AI. It supercharges their ship, gives Brian what can only be described as temporary superpowers, and sets them out to get into a dogfight at the moon's core with a malevolent swarm of human-hating nano-machines. 

The ensuing laser battle is astonishing to behold, but it still boils down to a hard truth: one of them is going to have to stay behind in the lander to detonate the EMP and put a stop to the swarm for good. Brian has decided to sacrifice himself, but someone else has other plans.

K.C., a man who has spent his whole life having his scientific beliefs treated like a joke, who no one ever thought would amount to anything, has finally gotten to see space — and see his research and life's work validated. K.C. has, in the last few days of the film's narrative, lived more life than he had in all the years previously since birth. That's why he can't let Brian or Jo stay behind when they have children on Earth that need them. Brian must go back now as the main conduit to the moon's deep reservoir of knowledge regarding humanity's secret history. K.C. is going to stay behind and culminate the unlikely journey he embarked upon at the film's introduction.

He sacrifices himself defeating the swarm, making it possible for Brian and Jo to reunite with their families on an Earth ravaged by this global close call, but not unsalvageable for a new tomorrow.

But no one ever really dies, at least not in a universe where the moon isn't a moon but in fact a supercomputer that birthed the Earth. As the film closes, K.C. re-materializes in the same space Brian learned about the moon's true origins. Only now the operating system presents itself as K.C.'s mother and his cat Fuzz Aldrin. It explains that his consciousness has been uploaded into the moon's supercomputer and that his work is far from over.