Warning: Slight "Doctor Strange" spoilers ahead.

There's a moment in Marvel's kaleidoscopic comic book adventure "Doctor Strange," when the good Doctor (played by Benedict Cumberbatch), formerly filled with hubris and pride but significantly humbled by a devastating car crash and subsequent spiritual awakening in the far east, is warned of the dangers of messing with otherworldly magic. The severe, heavily robed figures tell him that if he dabbles in certain magical scenarios like, for instance, using the time-twisting Eye of Agamotto, he could create parallel universes, alternate dimensions, and the like. It's meant as something of a throwaway line, mostly to give the audience a heads-up that, yes, Doctor Strange is going to use the Eye of Agamotto and, yes, it will be very cool. But embedded within the exchange could be the key to the future of the Marvel Cinematic Universe.

Even if you've never read a comic book in your life, you probably know that there are several different "universes" of comic book heroes. Recently, Marvel bent over backwards to annihilate these alternate universes in the convoluted Walking Dead" mastermind Robert Kirkman, and the "1602" universe, which was overseen by certifiable genius Neil Gaiman and imagined the Marvel heroes in Elizabethan times.

My point is this: depending on the creative team behind the book and the timeline/universe that they're playing in, there could literally be dozens of incarnations of your favorite superhero, sometimes just depending on the adjective that comes before that comic book's title (i.e. "Astonishing X-Men," "Uncanny X-Men," etc.)

So far, in the Marvel Cinematic Universe, things have been kept comparatively clean. The only dissonance has come from the times the characters have been brought to life outside of the company, like the recent, ultimately futile attempts at reviving the "Spider-Man" brand, and the endless "X-Men" sequels Fox produces. (Thankfully, next summer's "Spider-Man: Homecoming" returns the character to the Marvel Cinematic Universe after a brief, unforgettable appearance in this summer's "Captain America: Civil War.") There is, as far as we're concerned, one Marvel Cinematic Universe -- it was started by folks like Peggy Carter (Hayley Atwell), Howard Stark (Dominic Cooper or John Slattery, depending on how old he was), Hank Pym (Michael Douglas), and Captain America (Chris Evans) -- and has continued with Tony Stark (Robert Downey Jr.), Thor (Chris Hemsworth), Hawkeye (Jeremy Renner), and, now, Doctor Strange (Benedict Cumberbatch).

Marvel Studios has done an incredible job of keeping all of these characters and all of these films inside the framework of a single, relatively concise narrative. What's more, they've been able to catch you up to speed so that, even if you haven't seen "Avengers: Age of Ultron," you'd probably get the gist of "Ant-Man." It's sort of incredible. And while the Marvel Cinematic Universe has recently allowed for more tangential storytelling, like with the "Guardians of the Galaxy" films, there are repeated promises that it will all converge in one beautifully orchestrated superhero free-for-all (most likely "Avengers: Infinity War" or its direct sequel). But what if "Doctor Strange" just opened the door for something altogether, well, stranger?

There are some practical realities to first consider: no matter how much Robert Downey Jr. loves buying yachts, at some point he's going to get too old, too tired, or too expensive to keep portraying billionaire industrialist-turned-Avenger Iron Man. Similarly, other actors associated with the MCU have expressed their desire to do other projects or to just hang up their respective capes/rocket boots for a little while. These movies are a physically demanding slog for pretty much everyone involved. When I saw writer/director Joss Whedon on the set of "Avengers: Age of Ultron," it looked like he hadn't slept since the first movie came out. Eventually, these actors will need to be replaced, but Marvel Studios, in their infinite wisdom, might not want to wholly abandon the characters themselves.

And "Doctor Strange" might have given them the perfect "out."

Imagine a Marvel Studios opening with that exchange from "Doctor Strange" about all the alternate dimensions that he could potentially open up. And then imagine a smash cut to a new "Iron Man" movie, except this time Iron Man is an African-American teenage girl named Riri Williams. Or Thor is a woman. Or Gwen Stacey or Miles Morales is Spider-Man. All of these things happen in the comic books. Now they could happen onscreen, thanks to a some expositional dialogue in "Doctor Strange."

It's kind of genius, because this could allow for these alternate versions of your favorite character, while the original characters are still, presumably, in the main thread of the Marvel Cinematic Universe. And it wouldn't just facilitate new, alternate universe characters to enter the fold. It could also just give the regular actors some downtime. Chris Evans could take 10 years off to make "difficult" independent films and a bid for Oscar gold, and after he's feeling fully rejuvenated and refreshed, can return to the fold (maybe he'll give Bucky or Sam Wilson the shield for a while; both have been Captain America at different points in the comics). And where was Cap during those 10 years? In one of the alternate dimensions that Doctor Strange opened up in this movie.

The possibilities are limitless. Doctor Strange as the personal physician for Queen Elizabeth or a brain-craving zombie? Both are possible now. How probable they are remains to be seen; Marvel Studios likely wouldn't want to distance themselves too much from the core brand, although just imagine a "1602" movie by "The Witch" director Robert Eggers or South Korean filmmaker Chan Wook-Park taking a crack at a story set in the "Noir" universe. It's almost too much to fathom.

So in the next few years, if Marvel Studios announces some radical reinventions of its favorite characters, bold new casting choices, or just some left field weirdness, you can probably trace it back to this moment in "Doctor Strange.

"Remember: Doctor Strange is warned of what could happen and he does it anyway. Sure, the world is in jeopardy. But in saving Earth he may have substantially expanded the Universe. The Marvel Cinematic Universe, that is.