Back to the Future The Movie

The Back to the Future trilogy is a comedic science fiction film trilogy written by Bob Gale and Robert Zemeckis, directed by Zemeckis, and distributed by Universal Pictures. The plot follows the adventures of high-school student Marty McFly (Michael J. Fox) and scientist Dr. Emmett Brown (Christopher Lloyd) as they use a modified De Lorean automobile to time travel to different periods in the history of Hill Valley, California.

The first film was the highest grossing film of 1985 and became an international phenomenon, leading to two sequels which were filmed back-to-back and released in 1989 and 1990 respectively. The trilogy is widely noted for its irreverent comedy, eccentric characters and ability to incorporate complex theories of time-travel without confusing the audience.[citation needed] Though the two sequels did not perform quite as well at the box office as the first film, the trilogy remains immensely popular after 20 years and has yielded such spin-offs as an animated television series and a motion-simulation ride at the Universal Studios theme parks in Orlando, Florida (now closed); Universal City, California (closed on September 3, 2007), and Osaka, Japan.

Part 1

In Part I, 17-year-old Marty McFly is accidentally sent back in time to 1955 in a time machine built from a De Lorean by eccentric scientist Doc Emmett L. Brown. Upon arriving in 1955, he inadvertently causes his mother to fall in love with him, rather than his father.

To make matters worse, Marty did not bring back any extra plutonium to power the time machine, so he must find the 1955 version of Doc Brown to help him out. Not only is his own existence in danger (Marty must get his parents together or he will never be born) but he also runs the risk of being trapped in 1955 if he cannot harness a bolt of lightning that is known to strike the clock tower.

Part 2

In Part II, Doc Brown travels with Marty to the year 2015, where he has discovered Marty's family is in ruins. Marty buys a sports almanac containing the outcomes of 50 years worth (1950-2000) of sporting events.

However, Doc catches him and throws the almanac in the trash, where the aged Biff Tannen finds it. While Marty and Doc are at Marty's future house, Biff steals the De Lorean and gives the book to himself at some point in the past. When Doc and Marty return to 1985, they find that Biff has used the almanac's knowledge for financial gain, which allows him to turn Courthouse Square into a 27 story casino, "own" Hill Valley, which becomes a crime and gang infested town, get away with the murder of Marty's father, and later marry Marty's mother.

Marty learns that Biff was given the book by an old man in 1955, so he and Doc go back to that date in order to steal the almanac from Biff before he can use it to destroy their lives. They accomplish this in a complex fashion, often crossing their own past-selves' paths. When the duo are about to travel back to 1985, a lightning bolt strikes the De Lorean and scrambles the time circuits, sending Doc back to 1885 and leaving Marty stranded in 1955.

Part 3

After finding out that Doc Brown is trapped in 1885, Marty sets out to find the 1955 Doc to help him fix the De Lorean (which has been waiting for him in a mineshaft for 70 years) and restore it to working order. Learning that Doc dies shortly after his arrival in 1885, Marty travels back in time to save Doc (who becomes a blacksmith) and bring him back to the future.

Unfortunately, Marty rips a hole in the fuel line, rendering the De Lorean immobile. Furthermore, Doc falls in love with schoolteacher Clara Clayton, and considers staying in 1885. Marty must convince Doc to come back with him and find a way to get back to his time before it's too late.

Time Travel Theories

The Back to the Future film trilogy presents a detailed local history of the fictitious city of Hill Valley and the genealogies of its residents.

Each event described in this timeline is either depicted in the films, novels, screenplays, or described in interviews of director/co-writer Robert Zemeckis and producer/co-writer Bob Gale.

According to Doctor Emmett Brown in Back to the Future Part II, whenever a time-traveler alters key events occurring in the past, they effectively bring an alternate timeline into existence at their point-of-entry, and their original timeline is erased, even though its events are not forgotten by the time-traveler. Thus, every time travel jump into the past depicted in the Back to the Future saga "destroys" a current timeline and "creates" a new one, although the term Doc Brown often uses to describe the deleterious effects of this process is "erased from existence". Travelling to the future will not create a new timeline. The time traveller will merely move forward along his current timeline.

Imagineer Bruce Gordon suggested in issue #108 of Starlog Magazine

that no second version of the time traveler exists until the time traveler goes back in time and sees himself in the past.

Timeline 1

This is the original, unaltered timeline. In this timeline, Biff becomes George's boss and continues bullying him.

Timeline 2

This is the timeline brought into existence by Marty's accidental time journey into 1955. It is the timeline that is current at the end of the first movie, before Doc takes Marty and Jennifer into 2015 to try to change it back. In this timeline, George becomes an author and Biff becomes a car detailer.

Eventually, Doc leaves for 1985 to fetch Marty and Jennifer. This creates Timeline 3 which begins at the Doc's entry point of 1985 and timeline 2 fades away.

Timeline 3

This is the timeline which Doc brings into existence by travelling to 1985 to seek Marty and Jennifer's help. In this timeline, the fate of the McFly children ought to have been greatly improved. Unfortunately, "Old" Biff's stealing the De Lorean and traveling back to 1955 retroactively changes the events of this timeline and bring Timeline 4 into existence instead. Biff quickly returns the De Lorean to 2015 undetected (before any past alterations have taken place), and Doc, Marty and Jennifer depart moments before it fades away.
Biff Tannen, whilst pausing from cleaning Marty's 4x4 Toyota for him, witnesses the De Lorean hovering briefly before taking off for the future. "Old" Biff, age 78, who has been waiting for this opportunity for three decades, steals the De Lorean and heads back to 1955 with Marty’s sports almanac, which Doc angrily threw into a convenient trash receptacle, bringing Timeline 4 into existence six decades in the past.

Biff returns the De Lorean to 2015.

His return to Timeline 3 appears to break the Doc's rules of time travel (he should have returned to 2015 in Timeline 4). However the "ripple effect" which would cleanse the timelines is slightly delayed (Biff had travelled to 1955 where his younger self is too young to gamble, meaning young Biff could not immediately act on the knowledge contained in the almanac until 1958). After a few seconds in Timeline 3, the "ripple effect" which turns timeline 3 into timeline 4 catches up with Biff and he gets erased from the timeline after having been presumably murdered by Lorraine in 1996 Timeline 4.

(see below)
Doc, Marty and Jennifer, who think their adventure is over unwittingly depart to an "alternate 1985" thinking they are going home.

They are unaware of the fact that Timeline 3 is collapsing around them and their trip to 1985 brings Timeline 5 into existence.

Timeline 4

This is the timeline Old Biff brings into existence in 1955 by arriving from 2015 in the stolen De Lorean, almanac in hand.

It is replaced with a virtually identical Timeline 5 on October 26, 1985 when Doc, Marty and Jennifer arrive from 2015, and observe the damage Biff has accomplished.


Something causes Biff's death, but exact details are unknown. A theory suggested by Bob Gale and Robert Zemeckis says that Lorraine found out Biff had killed George, and shot him out of revenge. This would seem to have the effect of erasing Old Biff from existence in 2015, as depicted in a scene deleted from Back to the Future Part II.

Timeline 5

This is the alternate timeline brought into existence when Marty, Doc and Jennifer return from 2015. This is referred to by Doc as 1985A, which is depicted in BTTF Part II. The key difference between this timeline and Timeline 4 is the simultaneous presence of two Martys (his doppelganger overseas in Switzerland at boarding school), two Docs (his doppelganger committed to a mental institution) and possibly two Jennifers, one who is still unconscious from what she has witnessed in 2015 and her 1985A doppelganger, if she has one, which is never seen or mentioned.

Biff, recalling the advice given by his future self, grabs his gun to kill Marty. A chase with Match, Skinhead and 3-D naturally ensues, and Marty escapes once again after learning it was Biff who murdered his father.

Doc and Marty head back to 1955 to put the history they remember back on track. Jennifer Parker is left behind, as Doc surmises that she will not be erased when 1985A is. At this point, Timeline 5 fades away, to be replaced by the nascent Timeline 6.

Timeline 6

This is the key timeline brought into existence when Doc and Marty arrive in 1955 to relieve Biff of his newly acquired almanac from the future, thus preventing Timeline 4 and Timeline 5 from coming into existence, but without disturbing Timeline 2 as Marty has previously accomplished.

The hover-converted De Lorean from 2015 and 1985A, with Doc on board, is unexpectedly struck by lightning just outside Lyon Estates and sent back to January 1, 1885 due to an on-board malfunction Doc neglected to correct.

This brings Timeline 7 into existence, seven decades further in the past. The lightning bolt damages the car's time and flying circuits and forces the car to spin quickly reaching 88 miles per hour, causing the time machine to disappear into the past, leaving behind a pair of spiral flame trails

Timeline 7

This is the timeline Doc and Marty exist in, separated by 7 decades of time, at the end of BTTF Part II and the beginning of Part III (i.e., before Marty’s trip back to 1885).

It is a timeline in which Doc lives in 1885, without Marty, for only eight months and almost seven days. As it seems the careful Doc's presence has little impact on past history (until 1955 when his De Lorean is unearthed), this timeline is nearly identical to Timeline 2 with Timeline 6.

Marty leaves 1955 and heads back to 1885 to rescue Doc. This act initiates the ultimate timeline, Timeline 8. Young Doc, with tangible secret foreknowledge, remains behind, leaving the timeline undisturbed.

He waits the necessary three decades until he may build the De Lorean/time vehicle, and avoids further contact with the McFlys until the 1980s as outlined above (Timeline 1 and Timeline 2). Although he may not know if he'll be shot by Libyan terrorists in 1985, but he does know he'll possibly be murdered by Buford Tannen in 1885.

Timeline 8

This timeline comes into existence when Marty arrives in 1885, to try to prevent the events that lead to Doc's death in Timeline 7 at the hands of Buford Tannen.

It is this timeline in which Doc and Marty appear for most of BTTF Part III. It is also the final timeline depicted in the trilogy, as the De Lorean will no longer travel backwards in time.

Since Marty chooses not to race Needles upon his return to 1985, the future is changed once again, and the alternate futures Doc and Marty have experienced in Timeline 2 and Timeline 3 are erased by this timeline. Note: Two De Loreans exist in this timeline for five days in 1885, from September 2nd when Marty arrived, until September 7th when he departed for 1985.

In a virtuosic display of uncharacteristic self-restraint, Marty decides not to race Needles, and avoids crashing into a Rolls Royce, thus erasing the future experienced in Timeline 2. Jennifer surprises Marty with a fax she retrieved from 2015 in that very timeline, and as it "ripples" into a blank sheet of paper, she discovers the hidden truth about time travel, exclaiming: "It erased!" Marty takes her to see the remains of the De Lorean.

Doc, Clara and their sons arrive at Marty’s crash site in their time locomotive to briefly check up on Marty and Jennifer. Jennifer and Marty show Doc the blank fax, and he dispenses some sound advice about its significance. The Brown family departs for times and places unknown.

The Lesson of this movie is, our future is in our hands, we should be aware of it, and take care ourselves, and in able to avoid regrets we should be dependable.