Robert Zemeckis must either be a lover of temporal paradoxes or an incurable masochist. It is quite difficult to guess which other personality trait could have given rise to a cinematographic epic such as The Back to the Future Trilogy, starring Michael J. Fox, Christopher Lloyd, and Lea Thompson.
Chronicling the adventures of the rash adolescent Marty McFly and the eccentric professor Doctor Emmett Brown, taking them from the Wild West, through the present, well into the 2000s, the three movies deal with every variation of every temporal paradox probably anyone has ever thought up. Probably the most impressive aspect of Zemeckis' style is that he tackles such a weighty issue with the sense of wonder one only gets from a Jules Verne novel as well as with a sense of amusement one only enjoys during the comic relief scenes of great dramatic works.
In the first movie, Doctor Emmett Brown literally "stumbles" onto the key to time travel. On November 5, 1955, Doc (as Marty McFly likes to call him), while standing on the toilet hanging a clock, falls and hits his head on the sink. When he comes to, he sees "a vision, a picture in my head of the device that makes time travel possible - the flux capacitor". Some thirty years later, Doc unveils his latest invention - "The one I've been waiting for my whole life." Within the stainless steel frame of a DeLorean motor car, Doc has built a time machine. When the car reaches a speed of 88 mph, the DeLorean shatters the time barrier, leaving a trail of flames behind it.
In the parking lot of the Twin Pines shopping mall, at exactly 1:19 a.m. on the morning of October 26, 1985, Doc's dream becomes reality. His dog, Einstein, becomes the world's first time traveller, going one minute into the future. Several minutes later Doc's young friend, Marty McFly, accidentally becomes the world's second time traveller, heading 30 years into the past and getting entangled in a series of events which ultimately require him to get his parents to fall in love. A minor subplot of the movie involves McFly 'inventing' rock & roll in a delightful anachronism possible only through time travel.
To send the DeLorean through time, Doc must create a nuclear reaction (utilizing plutonium stolen from terrorists) to generate the 1.21 gigawatts of electricity needed to power the flux capacitor. When Marty is stranded in the past, the 1955 Doc must find an alternative energy source, as plutonium is not readily available. Luckily Marty has some information on the weather from reliable sources, namely the future, and Doc channels a lightning bolt through the flux capacitor and sends the youth back to 1985.
Things get much more complicated in the second movie of the series. After McFly arrives back in 1985, Doc Brown shows up and whisks Marty to 2015. An Old Biff Tannen, McFly's enemy from the first movie, has stolen a futuristic sports almanac, disappearing into the past with it.
Returning to 1985, Marty finds that the present has been changed for the worse. Young Biff has become rich, courtesy of the almanac that a time traveling Old Biff gave him in 1955. Marty travels back to 1955 to put things right. After quite a bit of fighting, running around and indulging in Hollywood-style split-second coincidences which always seem to save the protagonist, Marty finally gets the sports almanac back from Young Biff, changing 1985 back to normal. However, upon his return to the present, Marty receives a message from Doc Brown, who is now in the Old West in 1885.
In the last movie of the series, Marty travels back to 1885 to rescue Doc. Upon his arrival, he inadvertently puts a hole in the gas tank of the DeLorean. Searching for a fuel replacement, Doc tries the saloon's 180 proof whisky, which promptly blows out the fuel injection manifold. Doc and Marty hit upon the idea of pushing the DeLorean with a steam engine. To increase the locomotive's power and speed, Doc creats special logs, chemically treated to burn hotter and longer. Seconds before the car hits 88 mph, Doc returns to the steam engine to save Clara (his 1885 girlfriend), and is stranded in the past as the DeLorean disappears through time. As Marty returns to 1985, the time machine is destoryed in a crash with a diesel train.
The series of events that lead Doc Brown to end up in the Old West are fascinating to say the least. The explanation can only be pieced together after having seen all three movies: Upon returning to 1955 for the second time, the DeLorean is caught in the same lightning storm that helped send Marty back to 1985 in the first place. With Doc at the wheel, a lightning bolt hits the time machine, causing an energy overload which scrambles the time circuits, and sends the vehicle, and Doc, to 1885. The overload also destorys the car's flying circuits. As the technology to repair the time machine does not exist in 1885, Doc buries the car in an abandoned mine, and uses several generations of Western Union to deliver a message to Marty, along with instruction for the '55 Doc to fix the DeLorean. In a sense, it is the 1985 Doc who teaches his younger self how to build the time machine.
Although one may regard the trilogy as nothing more than an entertaining series of Hollywood flicks, the Back to the Future series provides much food for thought, including questions as to the viability of time travel, the different interpretations of causality, the actual role of potential anachronisms, the paradoxes which crop up in the plot, the nature of quantum branches in time, as well as the hypertextual elements within the narrative of the movies.