Back to the Future: The Other Marty McFly Theorem

By Shawn Robare

November 10th, 1990, a red-letter date in my personal fandom of the Back to the Future franchise. Yes!  Of course!  November 10th, 1990!  That was the day I discovered my first time travel loophole in the Back to the Future movie trilogy continuity.  I remember it vividly.  I was sitting on the edge of my toilet reading a copy of Starlog, there was an entry in the letters column complaining about BTTF 3, I freaked out as my dad came into the bathroom, yelled at him to knock first, and when I went back to flipping through the magazine I had a revelation!  A vision!  A picture in my head!  A picture of two DeLoreans existing in 1885 simultaneously!  This is what makes time travel movies implausible: loopholes!  In all seriousness, the events described previously actually happened, I was in the bathroom reading the letters column in an issue of Starlog when I had a moment of clarity and realized that there are actually two DeLoreans in BTTF 3 at a point in the story when they desperately need another time machine.  Stop me if you’ve heard this.  So at the end of BTTF 2 Doc and the time machine get struck y lightning and sent back to 1885.  Doc hides the DeLorean in a cave for Marty to find while he’s stuck in 1955 (he gets that nifty telegram delivered moments after Doc is whisked away to alert him of this.)  So Marty find the 1950’s Doc, they uncover the DeLorean and fix it up (because of the years worth of dry rot to the tires, etc.)  Marty then takes this one back to 1885.  So here’s the thing.  The one that doc hid in the cave?  It’s obviously still there (it would have to be for Marty to find it in 1955.)  Thus two DeLoreans and no need to make some time traveling train.  My 13 year-old mind was blown.


Over the years I’ve realized that this isn’t a huge revelation, if only because I’ve become more jaded as I age and would be the first person to point out that with all the twists and turns of the 2nd and third BTTF films there were bound to be plot-holes.  Time Travel is a fickle story element that is nearly impossible to “get right”.  Hell, just consider the two DeLoreans.  Just using the basic logic of time travel, though the two can co-exist in the same time, there are special rules for say using parts of one to fix the other.  If you took a part off the one Doc hid in the cave to fix the one Marty brought back, it wouldn’t work.  As soon as you removed the part, it wouldn’t be there in 1955 for Marty to find intact right?  But, the opposite isn’t true.  Take a part off of the version Marty brought back to fix the one Doc hid and you don’t get into this displacement effect.  Maybe this is why it’s not brought up in the film, maybe Robert Zemeckis and Bob Gale realized this and decided to sidestep trying to explain it (the franchise was pretty confusing at it was at this point.)

All of this aside, I’ve always considered the first film in the franchise to be pretty tight and free of these pesky time travel loopholes.  In fact, after a hundred nerdy conversations with friends and family I was pretty certain that there was nothing new to ever discover in that first film.  Well, that was until I poked my nose in another issue of Starlog a few weeks ago and found an article discussing the two variations of Marty McFly in the first movie.  Though this revelation wasn’t reached on my own, thus sidestepping that Doc Brown toilet bonk Eureka moment, it still blew my mind none-the-less.  The article was titled “The Other Marty McFly”, was written by Bruce Gordon, and appeared in issue 108 from July of 1986…

Starlog 108 0

Marty Alpha

The gist of the article is that there are two Marty McFlys (which they label as one and two, but I’d rather call them Marty Alpha and Marty Beta), the main one that the movie follows back to 1955 and beyond (Alpha), and a slightly more mysterious second one that is seen towards the end of the film repeating the events from the beginning as Marty Alpha returns to 1985 a few minutes early in the hopes of saving Doc Brown from the Libyans (Beta.)  But aren’t these just the same Marty at two places?  Well yes.  And no.  Consider the ultimate end of the film after Marty finds out that Doc did indeed read the warning letter he gave him back in 1955.  Doc survives thanks to a handy bullet proof vest and Marty goes home.  But is it the same home?  Obviously not!  The McFly family that Marty Alpha grew up with are for all intents and purposes kinda losers…


His mom has a drinking problem, his dad is a beaten down pushover, his brother is a foul-mouthed slacker who works at Burger King, and his sister, well his sister hates taking messages for Marty.  But in the 1985 that Marty Alpha returns to his family is completely different…

Beta Family

His dad is a wealthy published writer, his mom is fit as a fiddle, his brother always wears a suit to the office and his sister, well, his sister has slightly better hair, less frumpy clothes, and doesn’t seem to mind taking messages quite as much.  Not only is his family more well off, but Marty is too.  His room might be identical, but this Marty has that sweet black 4×4 he always dreamed about!


The point here is that the Marty that grew up in this environment, with more successful siblings and parents, with a totally different world view, is in fact a different Marty that we get to know throughout the film.  Thus, Marty Beta.

Marty Beta

(for the sake of ease I thought it would be fun to have Marty Beta represented by the Eric Stoltz version of the character…)

The two are similar, but not the same.  They had vastly different experiences growing up and thus, who knows what happens when Marty Beta gets that DeLorean up to 88mph and blacks back to the past.  Similarly, the Doc Brown that Marty Alpha encounters in 1955 and then eventually goes on to become the slightly different Doc Brown in 1985, the one that is prepared for the Libyans with a bullet-proof vest and got a chance to “know” Marty before he was even born, would he have informed Marty Beta about the adventure he was going to go on that fateful night?  This is getting a little convoluted, but it’s just the beginning!

Bruce Gordon goes on to point out something about the opening of the BTTF film that I had never noticed before.  Though we plainly get a chance to see that there are two Martys at the end of the film, what if I said for a split second there are also two at the beginning?!  That’s right, there’s a hidden Marty during the original sequence at Twin Pines mall that can be seen in silhouette for a split second of screen time.  That’s right, go grab your DVDs or cue up this clip on youtube. Now, pause the footage right as the Libyans corner Doc, right before Doc throws his gun away.

Wha 1

You see that lit storefront between Doc and his big white van?  Pay attention to that little lit area and Marty Beta runs across that area…

Wha 2

Now in the interest of complete transparency I will be the first to admit that what we’re seeing is way more likely a mistake, a crew member scuttling across set in front of shooting by accident perhaps.  But just for a second, imagine that that IS another Marty.  Think about that placement for a second.  You see how the Libyan’s VW Microbus is on the left and Doc is on the right?  Now consider that when Marty Alpha comes back to 1985 at the end of the film and he runs up to the (now) Lone Pine Mall and he stops at the sign, spatially, where is he in reference to the Libyans and Doc?  That’s right!  In that same area!


But why would Marty Beta be skulking around in the background at the beginning of the film?  Well, it gets back to the differences between the two of them, and the differences in the two Doc Browns.  In Marty Beta’s world, the Doc that he hung out with knew he was going to eventually build a time machine, knew it would be made out of a Delorean, knew that he was going to get shot and that Marty was going to travel back in time, etc., etc.  That Doc knew that when Marty came back he altered the timeline by changing the outcome of his parents meeting and falling in love.  That Doc knew things he possibly didn’t want to know.  So maybe that Doc decided to read the letter that Marty left him, and then was extra prepared for that fateful night.


What if that Doc had a plan to set the timeline straight by tweaking the events just a bit, by say pre-loading the DeLorean with the extra plutonium he had on hand, knowing Marty would take it back to 1955.  Maybe he even gave Marty instructions to come right back without messing with the time line at all (as Bruce Gordon suggests in the Starlog article.)  That way everything would right itself to the true (Alpha) timeline.  If you remember, during the original mall sequence he has a realization to grab the extra plutonium right before the Libyans show up.  It was all in a yellow containment suitcase right beside the truck…


Well guess what is no longer on the ground beside the truck during the end sequence of the film?  That’s right!  The plutonium isn’t there!


Now I know what you’re potentially thinking, it just wasn’t in the shot by accident (the set dresser forgot to put it out, it was moved, etc.)  Again, you’re probably right.  But consider the fact that there are a lot of subtle details strewn throughout the film that illustrate that there are two different versions of Hill Valley in 1985.  There’s the obvious differences in Biff and Marty’s family, but there’s also some changes to the backgrounds in the sets!  The most glaring is the differences in the Twin Pines Mall (which becomes the Lone Pone Mall), but also the change in the clock tower.  At the beginning of the film when Marty is with Jennifer and the woman comes up declaring that they have to save the clock tower you can clearly see that the only thing wrong with the clock tower is the fact that it stopped working because of the bolt of lightning that struck it in 1955…


But during the events of the night when 1955-era Doc Brown is trying to get Marty back home he totally destroys a chunk of the ledge underneath the clock while attempting to connect the wires needed to harness the lightning…



Right as Marty returns to 1985 the first thing we see is that same clock tower, only now a chunk of the ledge is missing (there’s a modern helicopter in the below screen shot so you know it’s ’85)…


If Zemeckis and crew went so far as to include details like this, is it possible that he also intentionally removed the plutonium at the end, and possibly had a Marty Beta running across the background of the opening mall scene to illustrate the dual Marty time loops that are in the story?  Who knows for sure, but damn if it isn’t fun to think about!  If nothing else, Bruce Gordon’s article in issue 108 of Starlog afforded me the rare opportunity to find a new experience in a film that I thought held no more surprises for me, and that is pretty freaking awesome. I never considered Marty Beta and what his life was like, how different it most likely was…


  • Dude…

    • You see, there’s this corkscrew, and on one part is Marty Alpha, and on the other is Marty Beta… ;)

  • Eric Stettmeier


    • I love flipping through old issues of Starlog just for articles like this…

  • Hoover Iceeboy


  • I’m still voting Goldie Wilson for mayor.

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    I work at Biff`s and they were promoting the BTTF Slot machine last month and had a one off screening of the original movie at the cinema and a Delorean on site for a week. I noticed details in the movie I hadn`t seen before but not to this extent.

    • Oh cool, I finally had a chance to play that slot machine earlier in the year. One of my bucket goals is still to sit in a DeLorean, or at least get a picture near one. There was a guy down the street from me when I was growing up that owned one and I loved pedaling past his house on my bike to stare at it in the driveway.

      As for noticing the details in the movie, not sure what prompted this change for me over the last few years but I’ve been doing my best to have a laser focus for all of the stuff on screen that isn’t plot related. I guess I’ve gotten to the point with some of these flicks where I’ve seen them so much I can focus on the minutia :p


        I got to experience Universal in Cali in 2003 and went on the BTTF ride.


          I was on the tour shuttle thingy and saw this and it was not even mentioned.


            Lyon Estates

          • Nice! I think I saw a blurb about Hot Wheels releasing a version of Biff’s 1955 card in their Retro Entertainment series soon…

        • Awesome! Yeah, I feel like not having a photo with one of these is a serious hole in my pop culture cred ;)

  • My god. I thought I paid close attention to movies.

    For me, the biggest questions were these:

    When Marty first arrives at the parking lot, Doc drives the DeLorean out of the box truck. Being that the car fits into the truck so snugly, we can assume that the gull doors can’t open in the truck. Does this mean that doc drove the car into the truck and sat there waiting for Marty to arrive just do he could make a dramatic entrance?

    Also, why does Chuck Berry need to be reminded that he has a cousin with which he shares a surname?

    • Oh man, good point on the DeLorean in the back of the truck! Movie magic. Though part of me likes the idea of Doc waiting to make a grand entrance ;)

      Heck, not only Does Chuck and Marvin share a surname, they share a profession! Maybe Marvin is that annoying family member always copying Chuck and constantly telling him what he needs to do to “make it”. The one time when he had good news was during Marty’s jam… ;)

      • Poor Marvin. Where would Chuck be without him?

        Coincidentally, I happen to be wearing my Marvin Berry and the Starlighters shirt today. How’s that for synchronicity?

  • Retromash

    Hey Shawn. Attempted a Twitter chat with you last night about this but it’s very hard to succinctly explain complex time travel theories in less than 140 characters!

    So I was talking about the second Marty who is seen when the main Marty travels back 5 or 10mins early and arrives at the mall parking lot. Marty1 watches the new Marty2 escape the Libyans and travel back in time in the DeLorean. But this is in the new future that Marty has created where the McFlys are a successfull, well educated family and I feel it’s unlikely that the Marty from this new timeline would be ditching school and hanging out with a crazy old Doc. He’s probably at home studying or being a psuedo Alex P Keaton! And therefore he wouldn’t be there at the parking lot that night and therefore he wouldnt go back in time. Some people would say that Marty2 has to go back because if he doesnt then how does he fix the past etc (paradox loop). But it was only because he went back to the past in the first place that things nearly got mucked up. It ended up creating this whole new timeline. So if he now doesn’t go back at all then it means the paradox loop has been closed and everything’s back to normal, albeit with a new future.

    BUT then it hit me that if this new Marty2 didn’t go back in time then there would be two Marty’s in this new future timeline! That’s a bit awkward. Perhaps they would have to fight it out to the death. There’s an idea for a sequel. Or alternatively they could make a new sitcom called ‘My Two Martys’. Either way I started off this line of thinking trying to find a solution to something that I thought was a little problem with the ending of the film but now I seem to have made it out to be a much bigger and more confusing problem! Sorry about that. I’m going to go for a lie down now.

    • Lol, I love this thought process. Seriously, that Marty from the “new” 1985 with the successful family would be the same but different, different attitude, possibly a higher achiever like you bring up. I like to daydream that Doc let him in on his experiences with Marty 1 and that they formed a plan to fix the timeline that night even though that would mean Doc’s death at the hands of the Libyans…

      • Retromash

        Ah well now you bring up a very valid point which is that the Doc from this new timeline is the Doc who had Marty visit him back in 1955, so it stands to reason that Doc might find a way to make sure he and Marty became friends in the future and as you say perhaps he even let him in.

        I’m not going to even think about BTTF2 and 3 in this light until my brain has stopped hurting.

        • Amen! Or the possibility of Sam Beckett leaping into Marty right before he time travels back to 1955… ;)

          • Retromash

            Woah. Mind blown. Sam leaping into Marty? Would be great to leap into characters from films. Have you read Ready Player One? The bit where the lead character basically leaps into the role of David Lightman from Wargames is my idea of extreme awesomeness.

          • Yes! That was my favorite part of that book hands down. I think that idea, to basically have a Guitar Hero/Rock Band style game for movies and script dialogue is genius and I wish it existed now.

            As a kid, before my folks got a VCR I used to hold up my boombox to the TV and tape the audio off of my favorite movies so that I could listen to them at night while I layed in bed. I got to the point where I memorized some of them fully and could recite them from start to finish… :p

          • Retromash

            That is awesome. You could call it Filmaoke. I’m sure someone must have already called it that. I love that you did that. I had a similar experience with the official Rocky Horror Picture Show soundtrack which was a recording of the movie but with the audience participation recorded too. I still have the LP. I learnt the entire script and the audience lines too. I can still probably remember most of it. It’s incredible the power of audio and how little you have to rely on visuals sometimes. The power of imagination and all that.

          • Totally :)

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  • Steve

    Time paradoxes will be discussed forever. Good article and interesting idea. Fans!!! The BTTF forum is Back and can be found at

  • nerdlunch

    Starlog 154 has a sequel article about BTTF II. I’m still trying to see if there’s a third article.

    • nerdlunch

      Found the second follow up in issue 170.

    • Oh man, I haven’t dug that far into Starlog yet, going to check my issues now and read these!

    • Alright, I’m halfway through the followup article and I have a headache, but like with the first I think I have something to write about the whole idea. Thanks so much for pointing to these CT!

  • Tey1

    Marty beta’s theory is complete bollocks (sorry to say), wanna know why? Because in part 2 we see “marty beta” do exactly what marty alpha did, we see him play johnny b goode as well as being in the parked car with his mom and coming back to see george punch biff (just before alpha marty says “talk about deja vu, we see the beta marty smile then look at the picture followed by running to marvin begging him to play, so infact there is two dimensions, but not as far as a switch, its just marty beta (the original rich family marty), is gonna turn his to be parents life around.

    • Well, something to take into context with the sequel is that there are two Marty Alpha’s in the same place at the same time. When Marty goes back to 1955 to recover the sports almanac he’s seeing the version of himself that originally went back to the past in the first film, not the version that had the successful parents. The sequels compound the complexity of the various timelines tenfold.

    • Gavin Shepherd

      You could argue that because Biff messed up the timeline at this stage there was no other marty.

  • Spot_Man

    About the BTTF3, how would they store 2 time machines in the same place. Wouldn’t the universe, or if we’re lucky just our galaxy, be destroyed. The reason the 2 Jennifer’s, Docs, Biff’s and Marty’s didn’t is because they were not from the same universe. The DeLoreans were from the same universe so they couldn’t be any where near each other. What I think is likely is that Doc used parts from the DeLorean that was left for Marty and replaced them after he made his Time Train. There were very few usable parts of the crashed DeLorean. He had to use every part of that one or he would create paradoxical anachronism. Since one is destroyed it is no longer a time machine. From what we see travel in in time without some kind of barrier between you and the timestream is deadly. How else did Doc travel to the future? The Time Train was not built in 1885, it is built to somewhat blend in to that time period. What is also of interest is Doc is happy to see Marty despite the ability to time travel and being each other’s best friend Doc apparently hadn’t seen him in awhile. Of course, he could just be more masterful with time and realizes he’s a dimension traveller. Events in one time line will be different yet similar in another. That’s why he says the future is what you make it. This could also be a way of telling Marty he won’t allow him to time travel. Clara instead of dying just disappears from the timeline, Doc is from the future and is supposed to be dead, Jules and Verne my be the first time children ever born. They are free to explore timelines because they don’t exist from a certain point of view.

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  • Gavin Shepherd

    Marty mcfly been in the back ground of the first footage when doc first cobtronts the libeyans Is NOT Marty. 2 people walknig by. and for it be be marty according to the pic he would have to be more a less in front of the headlites of the truck.. Hence of screen not on the first photo

    • First off, from this piece: “Now in the interest of complete transparency I will be the first to
      admit that what we’re seeing is way more likely a mistake, a crew member
      scuttling across set in front of shooting by accident perhaps.” Second, the shadowy figure that runs by that storefront at the start of the film would be Marty Beta, not Alpha, so he could have come in from any number of places with the foreknowledge of what transpires. Either way, it’s just a fun theory to think about. Just saying…

      • Gavin Shepherd

        Theres at least 2 people unless its a 3rd Marty realising his mistake and running out.

        Theory aswell is, when Marty sees himself go back to 1955 by this point the Marty we see is the marty with the different parents so Marty may be different resulting in a different adventure attitudes played out slightly different. Easier or harder. If they ever did a remake Id love to actually have them put these theories into the movie

        • Yeah, I agree I think it could be fun to delve even deeper into these ideas if they ever did remake or reboot the series. It would be a way to bring something new to the table without having to come up with any “new” story elements. Just go deeper into what’s already there :)

          • Gavin Shepherd

            It woudl be a great concept, a kind of eerie thought if they played on this But in some ways we could also say that at the moment when Marty sees himself go to 1955, this is jsut normal marty. the timelines and parents rendering him still the sme marty, as not yet altered. When he wakes up the timelines have sorted themselves out.. But who knows.. We’;ll never know its that kind of stuff you just wouldnt wanna experiment with

  • Gavin Shepherd

    In the first part of the article it say about 2 deloreans ion 1885.. Okay ye but they cannot use the one in the cave instead of a train cos if they use that to go back to 1985 One no fuel or big enough tanks..
    2 If they move it then Marty will not find it with doc in 1955 to go to the old west

    • Yeah, tried to address that as well here: “Just using the basic logic of time travel, though the two can co-exist
      in the same time, there are special rules for say using parts of one to
      fix the other. If you took a part off the one Doc hid in the cave to
      fix the one Marty brought back, it wouldn’t work. As soon as you
      removed the part, it wouldn’t be there in 1955 for Marty to find intact
      right? But, the opposite isn’t true. Take a part off of the version
      Marty brought back to fix the one Doc hid and you don’t get into this
      displacement effect.”

  • David Gorski

    not sure if this is mentioned in the article ( i skipped ahead to the comments and plan to go back and read the whole thing after i offer my two cents ) but if the delorean hadnt died and marty was able to start racing toward the cable when doc’s alarm went off, marty would have hit the cable way too early. that’s just one of the things that’s bothered me for the past 31 years

  • Tony Hulse

    You cant do that. If you take the vehicle and move it from the spot you left it after Marty arrives in the past, you could alter the future and thus Marty never coming to the past, causing a paradox and timeline overwrite. Therefore, you have to keep it in its spot and let the course of things take place to ensure Marty does come to the past.

    You also have only seen a portion of the story, you do not know if Doc got all the data that the events would happen as they did so he could put them in place. Sort of like tracing an image on paper. He could have also wiped Marty’s memory after he divulged the information.

    Doc could also be repairing time and the timestreams that you haven’t seen are changed versions of the reality you thought was prime.