Mission: Impossible — The Final Reckoning Finally Explains The Franchise's Biggest Mystery

Contains spoilers for "Mission: Impossible — The Final Reckoning"

When "Mission: Impossible — The Final Reckoning" picks up shortly after "Mission: Impossible — Dead Reckoning Part One" ends, the powerful artificial intelligence known as the Entity still poses a massive threat to humanity, but Ethan Hunt (Tom Cruise) has managed to get the key away from Gabriel (Esai Morales). This will allow him to access the Entity's source code, which is located on a sunken Russian submarine. What few could've imagined going into "Final Reckoning," however, is how important "Mission: Impossible III," one of the best movies in the franchise, is to this twist in the new film's plot.

The franchise's third film involves Ethan stealing an item called the Rabbit's Foot. It's never explicitly mentioned what it is in the film, although Benji (Simon Pegg) says it will lead to "end-of-the-world kinda stuff." Ever since then, the Rabbit's Foot has remained one of the franchise's biggest mysteries, something many fans have mentally hand-waved away as a vague MacGuffin. It didn't really matter if it was a bomb, a bioweapon, or something else; it just existed to move "MI:III's" plot forward. But "Final Reckoning" reveals it was consequential after all, as the Rabbit's Foot is the origin of the Entity itself.

The world-ending terror hidden inside the Rabbit's Foot was a prototype version of the massively powerful artificial intelligence now plaguing Ethan and company. In the 20 years between "Mission: Impossible III" and "Final Reckoning," the Entity continued to grow until it could begin accumulating the nuclear arsenals of various countries. When planning your next "Mission: Impossible" rewatch marathon, you may want to change the order so that the third one comes right before "Dead Reckoning." After all, in a sense, that and "Final Reckoning" are an "MI:III" redo, as Ethan once again has to steal the source code, this time out of a submarine, to stop the Entity.

It's a common trope in pop culture for heroes to make their own villains. Batman causes Joker to fall into a vat of acid; Luke Skywalker's actions cause Ben Solo to turn to the Dark Side; and Ethan Hunt's theft of the Rabbit's Foot inadvertently allows it to grow into a world-ending threat. Ethan was originally tasked with stealing the Rabbit's Foot in "M:I:III" by Owen Davian (Phillip Seymour Hoffman). In the end, Davian dies and the Rabbit's Foot winds up in possession of the Impossible Mission Force.

Ethan undoubtedly thought he was doing the right thing turning over a powerful weapon (that he had no idea was an AI) to the United States government in 2006. He didn't know that Denlinger (Cary Elwes), the director of the country's National Intelligence, would begin to unleash the AI, still in its infancy, against foreign threats. This included using it against the Sevastopol submarine in 2012, which is when it gained sentience and sunk the vessel so that its source code, the only thing that could defeat itself, would be housed safely at the bottom of the sea.

Retconning the Rabbit's Foot to be an AI prototype that Ethan helped unleash adds a personal angle to "Final Reckoning's" story. But while he inadvertently brought armageddon to the world's doorstep, no AI is a match for the living embodiment of destiny that is Ethan Hunt.

It's unlikely that the team behind "Mission: Impossible III" intended the Rabbit's Foot to be an AI. After all, the vial it's in is marked "Biohazard," which doesn't really make sense unless it was labeled as such to throw people off the scent of what it truly was. (Of course, it does become a general threat to all life as we know it, which in turn makes it a hazard to all biological life, but we digress.) That said, there is a line in "M:I:III" that helps connect the Rabbit's foot to "Final Reckoning" in a fairly clever manner.

When asked what the Rabbit's Foot is, Benji describes it as an "unstoppable force of destructive power that would just lay waste to everything ... So whenever I see, like, a rogue organization willing to spend this amount of money on a mystery tech, I always assume ... it's the Anti-God." The term "Anti-God" becomes particularly prudent, as the Entity has formed its own doomsday cult in "Mission: Impossible — The Final Reckoning." These are individuals who want to aid the Entity in bringing about the end of the world, giving the threat an almost religious connotation as we see them try to prevent Ethan and his allies from halting the evil AI's mission.

The Entity has literally become an Anti-God that wants to end all life. Fortunately, "Mission: Impossible III" was so vague in its description of the Rabbit's Foot, it was brought back virtually seamlessly all these years later.

"Mission: Impossible — The Final Reckoning" is in theaters now.