Today — Oct. 21, 2015 — is Back to the Future Day: the moment when Marty McFly arrived to the futuristic world of Back to the Future II. From here on out, the franchise's cinematic timeline remains an open question.

Let's get this out of the way: If series co-creators Robert Zemeckis and Bob Gale have anything to say about it, there will never be a Back to the Future Part IV. "We don't want to make another one, and we don't think the public wants to see one," says Gale. "That can't happen until both Bob and I are dead," says Zemeckis.

But as ironclad as these refusals might be, the real history of the Back to the Future franchise is, perhaps appropriately, a little more complicated. Since the release of Back to the Future Part III in 1990, the story has been continued in pretty much every other medium: television, theme parks, comic books, video games, and even card games. Here's a brief trip through the many split timelines of the Back to the Future franchise.

Back to the Future: The Ride

In Universal Studios' theme-park continuation of the Back to the Future narrative, Doc Brown (Christopher Lloyd) invites his guests to track down the time-traveling Biff Tannen (Thomas F. Wilson) and chase him back to 1955. The ride begins in the 2015 of Back to the Future Part II, but quickly jumps to Hill Valley during the Ice Age, then the Late Cretaceous Period, and finally back to the "present" of the early 1990s.

This plot is obviously just a gossamer-thin framework for a fun theme-park ride — but if you're interested in the overarching narrative of the Back to the Future franchise, there are a few fun tidbits. Despite the open-ended conclusion of Back to the Future Part III, Doc Brown, his wife Clara, and their kids have settled down in the year 1991 to launch the Institute of Future Technology. And whatever Marty McFly is doing following the events of the trilogy, it doesn't seem to have much to do with time travel; Michael J. Fox appears only in footage culled from the original movies, pulling the central protagonist out of the story for the first time.

Alas, Back to the Future: The Ride was shuttered in 2007 to make way for The Simpsons Ride. Nevertheless, the video that was used on the ride is readily available. (It's not quite as effective without the motion simulator.)

Back to the Future: The Animated Series

Another story set shortly after the events of Back to the Future Part III, the animated series — like the ride — posits that Doc Brown and his family settled down in 1991 Hill Valley.

Michael J. Fox and Christopher Lloyd didn't return to voice Marty and Doc Brown. (Marty is voiced by David Kaufman, who now provides the voice of the title character on Nickelodeon's Danny Phantom; Doc Brown is voiced by Dan Castellaneta, best known as the voice of Homer Simpson.) Still, The Animated Series' fidelity to the continuity of the films is impressive; Mary Steeburgen, Thomas F. Wilson, and James Tolkan reprise the roles of Clara Brown, Biff Tannen, and Principal Strickland. Brief live-action segments at the end of each episode even feature Christopher Lloyd as Doc Brown (alongside some seriously terrible green screen).

The Animated Series has been unavailable on home video for years, but the latest Blu-Ray set — dubbed "The Complete Adventures" — includes each of the show's 26 episodes. It's an intriguing curiosity, but it's definitely only for Back to the Future purists; the average adult who enjoys the trilogy probably won't find this cartoon as riveting. (Seriously, who wants to spend time with Doc Brown's annoying kids? Didn't the first Back to the Future end by explicitly warning us that the kids of heroes turn out to be insufferable?) But The Animated Series does offer a reminder of just how broad and elastic this time-traveling premise could be. Over the course of two seasons, the characters dropped in on Ancient Rome, the Civil War, the Oregon Trail, and a futuristic cruise ship captained by Marty's great-granddaughter in 2091.

Back to the Future: The Card Game

One of the greater oddities in the Back to the Future canon, this licensed card game — now out of print — cast players as the descendants of characters from the movies: Doc Brown's son Verne, Marty McFly III, and even Tiffany Tannen, the daughter of Lorraine and Biff from a timeline in which Lorraine and George McFly are split.

Today, The Card Game is notable mainly for the novelty of each player's ultimate goal: preventing Doc Brown from inventing time travel. That's right: The Card Game tasks Back to the Future fans with ensuring that Back to the Future never happens in the first place. That's heavy.

Back to the Future: The Game

Back to the Future: The Game — released in five episode-length installments throughout the first half of 2011 — began with one major feather in its cap: It was created with the assistance of series co-creator Bob Gale. The series begins in 1986, just months after Doc Brown ventured off through time. As Marty sorts through Doc's things, he learns that Doc has been imprisoned and marked for execution in 1931 Hill Valley — and hops into the DeLorean to go back and make things right.

It's a winding, twisty narrative that was clearly made with great reverence for the original franchise. Christopher Lloyd returns as Doc Brown, and impressive Michael J. Fox soundalike A.J. Locascio voices Marty (though Fox himself later pops up as Marty's ancestor). As a game, The Game is uneven, shuffling players through tightly scripted scenarios between cutscenes. But as the closest thing we're likely to get to a Back to the Future Part IV, it's a worthy successor to the franchise.

LEGO Dimensions: Back to the Future

In May, Christopher Lloyd reprised the role of Doc Brown yet again in a commercial for LEGO Dimensions — a video game that invites players to experience a LEGO-fied version of numerous popular franchises, including Doctor Who, The Wizard of Oz, and Ghostbusters.

Among the franchises tapped for inclusion is Back to the Future, in a level that reenacts the original movie's narrative with a few kid-friendly tweaks. (Doc Brown dodges a volley of bullets from the Libyan terrorists, only to be knocked down by an errant baseball.) Strangest of all, the game's dimension-hopping premise inserts non-Back to the Future characters like Batman and Gandalf, who accompany Marty on his journey to 1955 Hill Valley. It's very, very weird to watch the Lord of the Rings wizard float around on a hoverboard.

Back to the Future: Untold Tales and Alternate Timelines

The 1990s saw a Back to the Future comic based on the animated series — but this new comic series, which arrives today, is designed to answer any lingering questions fans might have about the franchise. Once again, Bob Gale is involved in the creative process. "I said, 'If we're going to do this, let's go back to the characters. Let's do stories suggested by the movies, by the characters,'" said Gale in a recent interview. "People have always asked, 'How did Mary and Doc first meet?' That's a good story. Let's do that in the first issue. People have asked, 'How did Doc Brown's house actually burn down? Was it a fire insurance scam? What was that?' In issue #2 we tell that story. Issue #3, people have asked, 'Wouldn't have George and Lorraine wanted to find out what happened to Calvin Klein?' Well, we deal with that in issue #3."

In a world of reboots and sequels, how many more stories can a single film trilogy, released 25 years ago, possibly sustain? Judging by the many other Back to the Future stories that exist, the answer is apparently "infinite" — as long as you don't try to make another movie.

dataLayer.push({ 'event' : 'GAEvent', 'eventCategory' : 'Blaize', 'eventAction': 'UI component (control group)', 'eventLabel': 'Reg countdown catfish ad (ind-us61-control-4-pv)', 'eventNonInteraction': true });