Back To The Future Ending & All Changes To The Timeline Explained

Robert Zemeckis’ 1985 sci-fi adventure movie Back to the Future ends at lightning speed, or 88 miles per hour to be precise, with its protagonist Marty McFly returning to 1985. Marty spends the majority of the first Back to the Future movie stuck in 1955, after he accidentally drives his friend, Doctor Emmett Brown’s DeLorean time machine, 30 years into the past. Despite having a time machine, he’s not able to return to the future from 1955, as he doesn’t have access to the plutonium that the nuclear-powered DeLorean uses for fuel.

After tracking down the 1950s version of Back to the Future’s nuclear physicist Doc Brown, Marty enlists his help to travel forward in time to his own present-day life in the 1980s. Doc Brown devises a plan that involves a famous lightning strike that Marty is aware will hit the Hill Valley courthouse later in 1955, due to the event’s historical significance 30 years later. Using metal cables, Doc Brown channels the electrical energy of the lightning strike into the Delorean’s time travel mechanism. In this way, Marty McFly can return to 1985 and find history changed for the better.

How Marty McFly Goes Back To The Future

Lightning Doesn’t Strike Twice

When Back to the Future’s hero, Marty McFly, arrives in 1955, he soon searches Hill Valley for Doc Emmett Brown, the eccentric scientist whose invention sent him back in time in the first place. Marty naturally believes that Doc Brown will be able to help him return to his own time, in 1985. Doc has some bad news, though. Back to the Future’s Delorean time machine runs on plutonium, which isn’t as available to him in the 1950s as it will be decades later.

Doc Brown needs to come up with a way to generate 1.21 gigawatts of energy to flow into the Delorean’s flux capacitor, the part of the machine that facilitates time travel. Without access to nuclear energy, the only way Doc Brown can think of harnessing this kind of power is through a lightning strike. As it happens, Marty McFly has a flyer on him from 1985, which references a historical lightning strike on Hill Valley’s courthouse that will occur the week after he meets Doc Brown in 1955.

By attaching electric cables to the metal hand of the courthouse clock, Doc is able to conduct the requisite wattage of electricity to a wire that can connect with the DeLorean at the right moment, powering its time travel mechanism. It’s a close shave, but Marty manages to drive the Delorean at just the right speed to connect with Doc’s cables at the exact moment the lightning bolt strikes the courthouse, sending him back to 1985.

Why Marty Changes The Time He Returns To 1985 In Back To The Future’s Ending

He Plans On Saving Doc From A Terror Attack

As he prepares to head back to the future, Marty McFly changes the precise time at which he intends to return to 1985 by 10 minutes. Instead of arriving on the same date he left at 1.34 am, he sets the machine to arrive at 1.24 am. Marty makes this change because he wants to save Doc Brown from being sH๏τ by Libyan terrorists.

Just before he traveled back in time, Marty witnessed the shooting when he and Doc were attacked by terrorists who wanted their plutonium back. He aims to prevent it by arriving just in time to warn Doc Brown in advance of what’s about to happen. Unfortunately, when Marty returns to 1985, the DeLorean breaks down. He’s not able to get to the location where the shooting takes place in Back to the Future in time to stop Doc from getting hit.

How Doc Brown Survives Being SH๏τ At The End Of Back To The Future

He Ended Up Heeding Marty’s Warning


Doc shows Marty the DeLorean in Back to the Future.

Doc Brown, meanwhile, has already prepared for this eventuality. Doc survives at the end of Back to the Future by wearing a bulletproof vest, ensuring that he escapes the terrorists’ attack unscathed. He was aware that the attack was going to happen because Marty had given him a letter warning him about it back in 1955.

Although Doc initially ripped up the letter, fearing the consequences of him seeking to avoid future events, he apparently changed his mind. After he survives the shooting, he shows Marty the letter, which he’s taped back together to heed his friend’s warning.

What Happened To Marty McFly’s Parents After He Returned To His Time

Marty’s Intervention In 1955 Changed Their Lives For The Better

After he arrived back in 1955, Marty McFly suffered the indignity of meeting his parents as teenagers. What’s more, Marty’s mother Lorraine McFly developed a creepy attraction to him without knowing who he was, and he found his father, George McFly, to be the victim of bullying. With Marty’s help, however, George is able to overcome the school bully, Biff Tannen, and win the heart of his future wife Lorraine, securing his son’s future in the process.

When Marty McFly returns to 1985, he finds that his parents have changed for the better.

The confidence that beating Biff in a fight gave George had a dramatic effect on the future lives of the McFly family. When Marty McFly returns to 1985, he finds that his parents have changed for the better. George and Lorraine are happily married, with Lorraine physically healthy and no longer an alcoholic as she was at the start of the movie, and George a successful sci-fi novelist. Meanwhile, Biff Tannen, who was George’s supervisor in the original 1985 timeline at the start of Back to the Future, has become his personal valet.

All The Changes To The Timeline Marty Caused In Back To The Future

From Major Life Changes For The McFly Family To Minor Details In Hill Valley


An image of Marty McFly at the Twin Pines Mall sign

The turnaround in fortunes for Marty McFly’s family extends to several other aspects of their lives. For example, the family home has transformed from the run-down and overcrowded dump it was at the start of Back to the Future into a luxurious mansion. Marty’s brother Dave now has a successful office job, the family car is in great condition, and Marty even has his own Toyota SR-5, the 4×4 truck he always wanted.

All Back to the Future Timeline Changes Once Marty McFly Returns to 1985

Before

After

Hill Valley’s courthouse facade is intact

A piece has fallen off the facade of Hill Valley’s courthouse

Hill Valley’s shopping center is called The Twin Pines Mall

Hill Valley’s shopping center is called The Lone Pine Mall

Doc Brown is sH๏τ by Libyan terrorists for stealing their plutonium

Doc Brown saves himself from getting sH๏τ by wearing a bulletproof vest

Marty McFly’s family home is run-down and overcrowded

Marty McFly’s family home has turned into a luxurious mansion

Marty’s brother Dave has to catch a bus to a night job at a fast food chain

Marty’s brother Dave has a comfortable office job

Marty’s mother regrets marrying his father

Marty’s parents are happily married

Lorraine McFly is an overweight alcoholic

Lorraine McFly is healthy and not drinking

Biff Tannen is George McFly’s abusive work supervisor

Biff Tannen is George McFly’s personal valet

George McFly is a downtrodden employee

George McFly is a successful sci-fi author

The McFlys’ car is broken down

The McFlys’ car isn’t wrecked, and Marty has his own Toyota SR-5 4×4 truck

There are also some minor changes to Hill Valley due to Marty and Doc Brown’s actions back in 1955. Because Marty McFly ran down one of Otis Peabody’s pine trees on the land where Hill Valley’s mall would later be built, when he returns to 1985, the name of the mall has changed. Whereas before it had been called The Twin Pines Mall, now it’s named The Lone Pine Mall. In addition, there’s now a piece missing from the facade of Hill Valley’s courthouse, which Doc Brown knocked off as he was trying to wire up the courthouse clock.

Why Doc Brown Takes Marty And Jennifer To The Future In The Ending Scene

Doc Needs Them To Do Something About Their Future Kids


Marty and Jennifer at the end of Back to the Future

Before Back to the Future ends, there’s time for one more time travel scene, when Doc Brown arrives unexpectedly in front of Marty McFly’s house in 1985, asking him to travel forward in time with him. Marty is encouraged to bring his girlfriend Jennifer, who was recast for Back to the Future sequels, along with him, since what he and Doc Brown will be doing in the future concerns her too.

In Back to the Future Part II, it’s revealed that Marty McFly’s son Marty Jr. is going to take part in a robbery with Biff Tannen’s grandson Griff in 2015 if the older Marty and Doc Brown don’t intervene to stop him.

Doc Brown is cryptic about the reason why Marty and Jennifer have to come with him to the future. He simply tells them, “It’s your kids, Marty. Something has got to be done about your kids.” It’s never made clear in the movie what’s wrong with Marty and Jennifer’s kids. On the plus side, Doc has confirmed ahead of time that the couple is going to stay together and start a family.

What Back To The Future’s Ending Really Means

Our Actions In The Present Will Determine Our Futures


Marty and Jennifer in the front of the Delorean with Doc Brown in Back to the Future

The essence of Back to the Future’s ending is that events in the past or present can radically alter the trajectory of our future. Without Marty McFly’s intervention in his parents’ teenage lives in 1955, they wouldn’t have turned out to be as happy and successful as they are at the end of the movie. In Back to the Future’s final moments, Doc Brown apparently wants Marty to change history again with a similar intervention in the future, to alter the trajectory of his kids’ lives.

Back to the Future’s sequel doubles down on this interpretation of time travel, with a further retcon alteration to Hill Valley’s timeline to 1985 via the meddling actions of an elderly Biff Tannen. Biff steals Doc Brown’s Delorean to travel back to 1955 and give his teenage self a one-up on sports bookies, completely transforming his future, as well as the future of those around him. It takes more meddling from Marty and Doc to fix the problems Biff has caused.

As with various storylines throughout the movie trilogy, this plot point underlines the real meaning of Back to the Future’s ending. Our actions in the present necessarily affect the future, however we decide (or don’t decide) to act. So it’s better to act with as much awareness and foresight as possible, in order to shape our futures towards a positive outcome.

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