Time travel has never been the easiest story telling device to get right, with it often becoming far too complicated, a story crutch, or simply nonsensical for the actual plot. One story that really got it right however is Back to the Future, a cultural classic that no only re defined what sci-fi movies could be, but also remains one of the best examples of time travel story telling we’ve seen to date.
Before we get into the various timelines that are created throughout the movies, it’s worth looking at the rules of time travel the Back to the Future movies establish and follow. Although over the years many fan theories have outlined a number of apparent plot holes or paradoxes a good number of them can be explained away by actually looking at Doc Browns own explanation of time travel (rather than how we imagine it works, or comparing it to other examples).
Whilst detailing how the various timelines to Marty in Back to the Future II, Doc. explains that each time someone jumps backwards in time they create a wholly new timeline, and thus destroy the version of events they left behind (in theory this applies no matter how big or small the changes the time traveler makes are). And so every time we see any character use a time machine to go back in time they are creating a wholly new timeline.
The original set of events, that we’ll refer to as ‘Timeline 1’, is pretty much everything that happened leading up to Marty’s first trip back in time in 1985. Based on what we eventually find out, across all three movies, we know that hill Valley was founded in 1850, with the McFly family moving from Ireland to America during the early 1880’s, and the infamous court house clock arrived in Hill Valley on September 5th 1885.
Hill Valley eventually grows into is your typical American town, and in 1955 a great storm hits striking (and pausing) the clock. On the same night George McFly and Lorraine Baines go to the Enchantment Under the Sea dance together, a few days after Lorraine’s father hit George with his car, after which Lorraine became infatuated with him (despite her more popular status and his rather isolated nerdy one). The two fall in love and by 1985 have three kids; Dave, Linda, and Marty.
George’s high school bully, Biff Tannen, continues to take advantage of George, and by 1985 is his supervisor who still takes credit for all of George’s work. George and Lorraine’s youngest child, the 17 year old Marty, is still at high school, dating Jennifer Parker, and works for (/is very good friends) with Doc. Brown, an eccentric and reclusive scientist.
As an audience we get the general sense that neither George nor Lorraine are overtly happy; Lorraine is implied to have a of drinking problem and George is unfocussed and is still being bullied by his childhood bully Biff, additionally their house is run down, and their three kids are portrayed as relatively unmotivated or unsuccessful.
As Doc calls Marty to meet him at Twin Pines mall at 01:00 AM on October 26th 1985, Doc reveals the DeLorean Time machine, shortly after Libyan terrorists (that Doc stole the plutonium, to power the time vehicle from) arrive, kill Doc and chase Marty, he quickly jumps into the DeLorean and accidentally sends himself back to 1955 – thus creating ‘Timeline 2’.
With Timeline 2 being the focal point of the first movie pretty much all of the set up, pre 1955, is exactly the same. After escaping 1985 Marty arrives in 1955 where the Twin Pines Mall he left behind is yet to be built and is instead still the Peabody farm (that Doc previously mentioned). Whilst driving away from the farm (and destroying one of the two pine trees at the farms entrance) Marty confusedly makes his way into the centre of Hill Valley. Once there he slowly begins to realise he really is in 1955, and comes across the 17 year old version of his father.
After seeing his father bullied by Biff (and deciding George is a total loser), Marty follows George and discovers he’s a ‘peeping tom’ who spies on Lorraine getting undressed. As George falls from the tree, where in the first timeline he would of been hit by Lorraine’s father’s car, Marty instinctively jumps to George’s rescue, pushing him out of the way and being hit by the car himself.
Marty wakes with his mother at his bedside, and assumes it was all a dream and that he is back in 1985. Unfortunately for him when the lights go on he sees his mother is actually a lot younger than she should be, and realises he is still in 1955. To make matters worse she is now infatuated with Marty rather than George, as it happened in Timeline 1.
Marty then goes to the 1955 version of Doc Brown for help repairing the time machine (so that he can get ‘back to the future’). But whilst they do so, Marty assumes the identity of Doc’s nephew ‘Calvin Klein’ in an effort to get his parents together (ensuring he and his siblings are eventually born).
After 1955 Doc and Marty fix the time machine and, utilising the lightning bolt that Marty knows will hit the clock on the night of the dance, he arrives back in 1985. He quickly makes heads for the all to save Doc form the Libyans (after 1955 Doc refuses to take a letter from Marty explaining his eventual death) When Marty reaches Doc, after seeing his past self escape in the DeLorean and head for 1955, he realises that Doc did actually read his letter in the past, and was wearing a bullet proof vest.
Soon enough Marty discovers that the Timeline 2 version of his family is significantly more successful and happier (and richer). As the first movie draws to a close, and everything seems to of wrapped up nicely in Timeline 2 Doc reappears from the future, telling Marty and Jennifer they have to back to the future with him, and thus begins ‘Timeline 3’.
In short the main differences between Timelines 1 and 2 revolve around Marty saving George from being by the car, and thus setting off a chain of events that (if they continued) would prevent he and his siblings from being born. But even after he ‘fixes’ everything Marty’s presence in the past continues to changes a huge amount of things from Timeline 1, namely getting George to stand up to Biff. This in turn ensured a much more confident version of his father, who went on to become a successful sci-fi writer. Marty running over one of the pine trees at Peabody’s farm also means that in Timeline two the mall is called ‘Lone Pines’ Mall rather than Twin Pines.
With George much more confident the McFly family is a much happier version of it’s Timeline 1 counterpart, additionally his siblings appear to have better jobs, Biff now washes the McFly family cars (instead of being George’s bulling supervisor), and Marty finally has the car he always wanted.
Pretty much as soon as Back to the Future II starts we learn how Timeline 2 plays out for Marty and Jennifer, and it isn’t exactly the happy ending we thought.
The day after Marty got back to 1985 he was coaxed (by being called a ‘chicken’) into a street race that not only damaged his hands (affecting his ability to play guitar), but ended up in a lawsuit, setting Marty up for a future of financial problems.
Consequently he and Jennifer get married in the ‘Chapel o’ Love’, go on to live a somewhat unsuccessful life (much like George and Lorraine in Timeline 1), and eventually both of their children end up in jail, thanks to Biff’s grandson ‘Griff’.
Learning of all of this Doc decides to travel back to 1985 (thus starting Timeline 3), intending to get Marty and Jennifer to go to 2015 with him and help stop their children getting into trouble. As Doc and Marty play out Doc’s plan (and take on the part cyborg Griff) Marty gets the idea to buy the ‘Gray’s Sports Almanac’, which chronicles all of the sporting results from 1950 to 2000.
Marty’s idea is to take the book back with him to 1985 and place a series of bets that he already knows the result of. Doc stops him from keeping the almanac however, and instead the two retrieve Jennifer and head back for 1985, assuming everything has been fixed.
In short up until Marty, Doc, Jennifer, and Einstein arrive in 2015, Timeline 3 plays out exactly as Timeline 2 does, and the only reason Timeline 3 exists is because Doc wanted to make sure Marty’s life (or at least the period after the next 30 years) turned out alright.
Unbeknownst to Doc and Marty however Grandpa Biff from 2015 overheard their conversation about the Sports Almanac, and decided to steal the DeLorean and give the almanac it to his 1955 self (copying Marty’s plan). And so when Doc, Marty and Jennifer arrive back in 1985 they quickly realise it’s a very different world from the one they left and work out that Grandpa Biff created Timeline 4.
The fourth timeline we see created is the first to be a drastically different version of events from what we already know. Although we don’t technically see much of it we learn that Grandpa Biff (from 2015) went back to 1955 and gave his teenage self the Sports Almanac, which in turn led to Biff’s business empire (BiffCo), his control over Hill Valley, murder of George McFly, and marriage to Lorraine.
This timeline exists as a direct result of Grandpa Biff’s travelling from 2015 to 1955, but when Marty, Doc, Jennifer, and Einstein leave 2015 for 1985 their own time jump (based on Doc’s rules destroys the reality they left and creates a new one) creates Timeline 5.
With Timeline 4 revolving around Grandpa Biff giving his former self the almanac, Timeline 5 follows suit, except this version has Jennifer, Einstein, Doc, and Marty (coming directly from Timeline 3’s 2015).
Pretty much as soon as he arrives Marty realises something is wrong with this Hill Valley, he quickly discovers that Hill Valley has descended into a lawless, almost dystopian version of it’s former self.
With Jennifer knocked out, Doc and Marty discover that once Grandpa Biff from 2015 (in Timeline 3) went back in time and gave his past 1955 self the Sports Almanac, the 1955 version of Biff went on to become a millionaire. He then turned his money into a business empire and now owns a giant hotel in the middle of Hill Valley as well as most of the town, and apparently the police force. We also find out that in this reality Doc. Brown has been committed to a mental asylum, that Biff went as far as murdering George McFly to finally marry Lorraine, and that Marty has been sent out of the country to a boarding school.
Doc works out (thanks to Grandpa Biff’s cane breaking in the DeLorean) what has happened, and decides they need to find out when this version Biff first got the almanac from his 2015 self, and then stop him using it. Marty quizzes Biff on when he received the almanac, who in turn reveals that when his ‘distant relative’ gave it to him in 1955 he also warned him of a ‘kid’ and ‘crazy scientist’ who might one day come asking about the almanac, and that if they did, Biff should kill them.
As Marty runs from Biff and his goons (now armed with the knowledge of when Biff got the almanac) he and Doc escape and head back to 1955, and with that jump into the past Timeline 6 is created.
The main differences of Timelines 4 and 5 again stem from the day of Enchantment Under the Sea Dance in 1955 (to the point where Doc even questions if this is a mere coincidence or if there is a possibility that there is something special about that day), and the majority of events Marty set in motion in Timeline 2 still happen up until the early 70’s, not counting Biff’s rise to power. In 1973 however Biff murders George McFly (who was on his way to collect a writing award), in the same year Biff marries Lorraine (who already has her three children with George) and sends Marty off to an oversees boarding school.
The sixth timeline plays out as the earlier part of Timeline 5 (where Grandpa Biff gives his younger self the almanac), except this time Marty and Doc are working behind the scenes to steal it back and stop 1955 Biff from ever using it.
After yet another chase involving Biff, Marty, hover boards, and manure Marty and Doc eventually succeed in getting the Sports Almanac from Biff, but just before they are able to (finally) head back to their 1985 (or at least Timeline 2’s version of it) the DeLorean is struck by lightning, and Doc along with the time vehicle disappear completely.
As Marty stands in the rain, yet again stranded in 1955, a car approaches and a man claiming to be from Western Union delivers a letter that has been held for 70 years with strict instructions to send it to that exact spot at that exact time.
The letter reveals that Doc has in fact been sent (via the lighting strike and a time machine malfunction) to the year 1885, and as a result has created Timeline 7. Interestingly Timeline 6 is the first timeline to feature two versions of Doc, Marty, and Biff at the same time.
Timeline 7 features the earliest changes to a timeline so far and see’s Doc living in the Old West. Presumably the events of Timeline 7 would more or less fall in line with Timeline 2 by the time 1955 comes around, given how Marty goes to Doc from 1955 for help (with that Doc having just sent the other Marty back to 1985).
Doc’s letter to Marty explains that he has been living in the year 1885, and works as a Blacksmith in a very early Hill Valley. He goes on to explain that he can’t get back due to damage to the DeLorean and that suitable replacement parts won’t be built until 1947, he adds he is quite content with his new life in his favourite time period. He has also hidden the DeLorean in a cave at Delgado mine for Marty (with the help of the 1955 Doc) to repair and get himself back to 1985.
Finally Doc asks that Marty not come back for him, and that once he returns to 1985 he should destroy the time machine as it’s far too dangerous (having already caused a huge number of problems). Although not exactly happy about it Marty agrees, but whilst he and 1955 Doc retrieve the DeLorean Copernicus (Doc’s dog in 1955) leads them to a grave just outside the cave.
The headstone reads; “Here lies Emmet Brown, died September 5th 1885, shot in the back by Buford Tannen over a matter of eighty dollars.” With September 5th being only a week after Doc writes the letter for Marty, he decides to go backwards in time to 1885 to save Doc form Buford ‘Mad Dog’ Tannen, and in doing so he creates Timeline 8.
Given that Timeline 7 leads into some version of Timeline 2, the only real differences here are Doc’s presence and resulting murder by Mad Dog Tannen, and of course Clara Clayton (Doc’s tombstone ends with “erected in eternal memory by his beloved Clara”) still being alive to bury Doc, having not fallen down Shonash Ravine thanks to Doc’s collecting her from the station. We later learn that in Timeline 1 (and presumably the others as well) no one collected Clara at the station, and after she lost control of her horse she died following her falling into the ravine, leading to it being renamed ‘Clayton Ravine’ by 1985.
After seeing the details of Doc’s murder on his tombstone, and the subsequent confirmation of both Doc’s presence in 1885 and Mad Dog Tannen’s reputation at the Hill Valley library. Marty and 1955 Doc decide Marty must travel back to the Old West and warn Doc of his fate.
After escaping a battle between Native Americans and Federal forces, cutting the fuel line on the DeLorean, and meeting his great grandfather Seamus McFly (whose wife looks suspiciously like Lorraine McFly – meaning the McFly men clearly have a certain type) Marty arrives in Hill Valley, and quickly goes up against Buford Mad Dog Tannen. Unlike his encounters with Biff, and Griff, Marty isn’y able to outsmart Buford, who proves a little more dangerous and is only stopped from killing Marty by Doc’s arrival.
After he saves Marty, Doc quickly learns of his fate, but also tells Marty that the broken fuel line isn’t as simple a fix as Marty would of thought (given that refined fuel won’t be easily accessible for years). After horses can only get the DeLorean up to around 30 miles per hour, the two decide that the only option is highjack a train and push the DeLorean up to the required 88mph.
Not long after this realisation, Doc ends up rescuing Clara Clayton from falling into Shonash Ravine, and almost immediately falls in love. Whilst Doc prepares the time machine whilst also wooing Clara, Marty ends up arranging a shootout at dawn with Buford Tannen and the picture of Doc’s gravestone switches to say ‘Clint Eastwood’ (his 1885 alias).
Eventually, after copying the actual Clint Eastwood in A Fistful of Dollars (the movie we saw alternate 1985 Biff watching in the hot tub) Marty escapes his shootout with Buford and gets Doc to the train. The two take over the train and begin to push the DeLorean as the engine gains speed.
Before Doc can get into the DeLorean with Marty however Clara arrives, and as she falls from the train and is quickly saved by Doc, the DLorean hits 1885 and sends Marty back to the future. Almost as soon as he arrives Marty is forced to jump from the DeLorean as a train smashes into it, finally destroying the time machine.
After Marty reunites with Jennifer, and avoids the ill fated drag race with Needles, Doc and Clara reappear in a flying, time traveling, steam train, accompanied by their two children Jules and Verne. Doc explains to Marty that everything has been fixed, nothing is set intone and that now both Marty and Jennifer’s future is whatever they make of it.
As implied by the ‘Erected in eternal memory by his beloved Clara’ on Doc’s Timeline 7 tombstone, we see Doc save Clara from falling into Shonash Ravine. Instead we see that when Marty returns to 1985 the ravine is now known as ‘Eastwood Ravine’, a tribute to his own heroics and sudden disappearance under the alias of Clint Eastwood in 1885.
We also see the drag race the 2015 version of Marty was coaxed into by being called a chicken, here however (having learned a few lessons throughout his time travelling) Marty doesn’t race, and therefore doesn’t crash into the Rolls Royce (which in Timeline 2 damaged his hands and the driver sued Marty).
The biggest thematic/character change in Timeline 8 is Marty actually learning something, Marty is the perfect hero throughout but even in the first movie he rarely learns form his mistakes (or event he mistakes of his parents), and is instead still hung up on more material things (like getting the car he always wanted), but by the end of the third movie we see he cares less about people calling him ‘chicken’ and is growing into his own person. The end of the third movie sets Marty up to take Doc’s advice and really make his own future.
The ninth timeline didn’t arrive until almost 25 years after the third Back to the Future movie, and features in a special in the 30th anniversary box set of the trilogy.
The short details Doc Brown’s efforts to fix the future (specifically the version of 2015 we saw in the second movie) and avert a Nuclear Holocaust in the year 2045. Via Doc’s message to Marty we learn that Griff Tannen accidentally caused this Holocaust by uploading a virus which set off every Mr Fusion in the world, eventually Doc fixes Griff’s mistake (making sure he goes back to jail). But as Doc celebrates his victory, he realises he still has the ‘Quantum Mind Jar’ that he meant to dispose of in 2075, after this discovery another Doc Brown appears (perhaps creating a 10th Timeline?), and as the two are confused at each others presences the short ends.
Back to the Future is one of the most iconic movie franchise of all time, and even though there a few plot holes here and there, overall the 9 (or more) Timelines are very well written, immensely complex and brilliantly thought out.