FAQ for
Back to the Future Part II (1989) More at IMDbPro »

The following FAQ entries may contain spoilers. Only the biggest ones (if any) will be covered with spoiler tags. Spoiler tags have been used sparingly in order to make the page more readable.

For detailed information about the amounts and types of (a) sex and nudity, (b) violence and gore, (c) profanity, (d) alcohol, drugs, and smoking, and (e) frightening and intense scenes in this movie, consult the IMDb Parents Guide for this movie. The Parents Guide for Back to the Future Part II can be found here.

There are three movies in the Back to the Future franchise. Back to the Future Part II was preceded by Back to the Future (1985) and followed by Back to the Future Part III (1990).

When Biff returns the DeLorean to 2015, it is the alternate timeline he returns it to, not the original one. We are unable to see any changes as they are all outside, and they did not spend much time in 2015 after that. Alternatively, from Doc and Marty's point of view, the ripple effect would need time to catch up. They will experience two different timelines - one where Biff returned the DeLorean to the original 2015, and one where the ripple effect had caught up and the DeLorean was returned to the alternate 2015.

According to the writers, Biff was killed (possibly by Lorraine acting in self-defense) in the new alternate timeline he had created. He would therefore have been dead in 2015, and the pain was that of being erased from existence. This is the same pain that Marty goes through during the dance in the first film. In the deleted scenes for the movie, Old Biff is seen collapsing and then fading out of existence a few moments later.

The DeLorean does not hit 88 by spinning; the force of doing so would have resulted in Doc being killed by the impact. Those who've watched that part of the film closely say that the DeLorean only wobbles and then pitches upwards slightly before vanishing, which would have been far from fast enough to get it up to 88mph. The most likely answer is that the three lightning bolts that struck the DeLorean gave it a power surge that overrode the need for it to accelerate to 88, by going straight into the flux capacitor and activating it.

Depends on how detailed and varied the statistics are. We only know that it has the scores of various games and the winners of some horse races. With small enough font, the almanac could accomplish this - or by using a cross table, which could fit a whole season of results on half a page. Old Biff tells Young Biff, "All you have to do is bet on the winner, and you'll never lose." This line seems to indicate that only winners across different sports are recorded in the book. It'd be pretty thin then, even for 50 years of statistics of "football, baseball, horse races, boxing."

Where is 2015 Doc?

Well there are 3 possible answers here.

1, He's dead.

2, He's alive, we just don't see him.

3, I'll explain in the next section.

I know what you are thinking. Doc was 65 in 1985, so he would have been 95 in 2015...unlikely (though not impossible) that he was still alive right? Read on...

How old is Doc?

When in 2015 the 1985 Doc does state he went to a "rejuvenation" clinic and "added a good 30 to 40 years to his life." Let's just say it was 40 years "added" to his life. Depending on how you use the word "rejuvenation" eg: to make young again; restore to youthful vigor. This would now make Doc 40 years "younger" than he really would naturaly be. Doc was 35 in 1955, so 65 in 1985. But now he is 40 years "younger". So the once 65 years old Doc is now only 25 by the time he and Marty go to 2015 together. Doc is now "younger" than 2015 Marty is. So he could very much stil be alive in 2015. Even if we say he only added 30 years to his life, he still would have been "young" enough to stil be alive in 2015. (I know, hurts the brain doesn't it?) Yes Doc still does look 65 (hair, etc), but he went to a "rejuvenation clinic" not a plastic surgeon. (which is why the subtle joke about when Doc peels off the "age makeup" and asks Marty what he thinks, Marty is clearly less than impressed as Doc pretty much looks exactly the same.)

Keeping all that in mind... Now for the 3rd answer to the first question.

Where is 2015 Doc?

3, Doc does not return to his original time. (see the end of BttF III)

Now going by what we have seen in all 3 films.

1, Einstein being the first time traveller does not bump into his future self. This is due to the fact Einstein does not go back to his original time (albeit only one minute). There is one Einstein before the time travel, zero Einsteins during the following minute, then one Einstein again when he "arrives".

2, Marty & Jen DO see themselves in 2015. However, they do eventually get back to 1985 (thier original time) so can exist in the future.

So where is 2015 Doc? Just like Einie in part I but unlike Marty & Jen in part III. Doc does NOT return to his original time, but instead decides to stay in 1885 in Part III, so he can NOT exist 30 years in the future. Thirty years after the events of the trilogy, Marty and Jennifer are 48 and living out their life in 2015, Doc would be married to Clara and (provided he is still alive), would be living in 1915.

We see only 3. At the point in which we see Old Biff give the Almanac to young Biff, there are only 3 Deloreans, the highest number *from our point of view* at a time during any period in the Trilogy.

(1) Delorean that Marty(1) took to 1955 to escape the Libyans.

(2) Delorean that Old Biff took to 1955 to give Young Biff the Almanac.

(3) Delorean that Doc and Marty(2) took to 1955 to Retrieve the Almanac.

The 4th Delorean in question (from 1885 in the mine) does not actually exist in this period and won't until Doc gets struck by lightning at 930 in the evening. When Doc is struck by lightning, the timeline instantaneously changes around Marty, in this new timeline, Western Union comes to deliver the letter at 931 to Marty and the Delorean is now inside the mine.

When Old Biff was in 1955 to give the book to Young Biff, that was in the timeline before Doc was in the past, Doc was not in the early history books and the Delorean certainly was not buried in the mine.

However, while it is *entirely true* that *we* do not ever witness a moment in the films where all four instances coexist, but the text "from our point of view" above should hint at a solution. Once the DeLorean is sealed in the mine in 1885, consider what it would detect (if it were in a position to witness the comings and goings of its former selves): over 70 years of peace, then (1) arrives, then (2) and (3) arrive in some order; (2) then leaves at 6:38, (3) leaves around 10 pm, and (1) leaves at 10:04. (4) itself leaves soon after that. If we grant that all three of those instances (1-3) continue to exist in the "final" timeline, then there should be no problem accepting this theory. Still not convinced? Consider the 100-year gap near the end of BTTF III when Marty takes the DeLorean on its final journey. 70 years into it, for a few hours, there are 4 instances of the car.

This question is actually one of the fundamental logical problems associated with the possible reality of time travel. These logical problems have actually lead to a number of prominent physicists publicly stating that time travel is an impossibility purely because there is no logical way to reconcile the varying paradoxes it would cause. In this instance, as stated in the prior paragraph, we the viewer are seeing events presumably as they happen for the first time. In this instance the fourth DeLorean would not exist until the DeLorean taken back from 2015 by the Doc and Marty has been struck by the lightning outside the tunnel. Once that has occurred the DeLorean will have been left left in the cave by Doc Brown in 1885 which means that the DeLorean will have already existed in the cave prior to Marty having gone back to 1955 the first time as it was left there 70 years earlier. The characters simply were not aware of its existence there until Marty is made aware by the Western Union telegram from Doc.

In other words, we experience time linearly from the perspective of Marty McFly. Most theories of time itself are not so linearly limited with all things always happening at all times. For the DeLorean to ever have existed in the cave in 1955 it would always have to have existed in that cave since being left there in 1885 and will always have to have been left in the cave in 1885. Thus we have a logical paradox.

There probably are, just in different places. Doc recorded Marty Jr.'s movements, went back to get Marty, then landed in a different spot to avoid a paradox.

At first, this appears to contradict Back To The Future (part 1) where Doc Brown demonstrates the time traveling capabilities of the DeLorean to Marty by sending Einstein 1 minute in the future, and when Einstein arrives, there is only one Einstein and not two. However, at no time ever does Einstein return back one minute to the past. He continues living on one minute in the future. We know that 1985 Jennifer and Marty return back to 1985, so their 2015 selves are most likely a continuation of themselves after returning back to 1985. Since Doc has every intention of returning Marty and Jennifer to 1985 there is no reason they should not exist in 2015.

It's not the number 99. The fire marks are the tread marks of the DeLorean when it goes back in time. Apparently the DeLorean does a loop and hits 88 MPH and goes back to the Old West.

Old Biff was given a reasonable amount of time to figure out how it worked. Turning on the time circuits is not a laborious task. Punching in the date should also be a very easy thing to do, and if he didn't get it right the first time, he could try again (as Doc did at the start of BTF I). Operating the time machine is so easy that Marty accidently traveled to 1955 in BTF I. Yes, Biff would not have known to travel to 88 mph, however, he most likely just sped up until he reached the exact number needed to power the time machine.

The Mr. Fusion question requires some speculation. At the end of BTF I (or beginning of BTF II) Doc powers Mr. Fusion using trash. However it is never stated that Mr. Fusion is needed to be powered after every time travel trip. One load could last several trips. Some people just assume this is true because Doc powers Mr. Fusion before returning from 2015 to the alternate 1985. It is also implied that Doc has made several trips in 2015. We don't know if Doc powered Mr. Fusion every trip he made. We also don't know when Doc got Mr. Fusion to power the time circuits. It was probably when he first entered 2015 so he wouldn't need plutonium anymore. So we don't know for sure whether Mr. Fusion is needed for every single trip. If this is true, than Old Biff would have no trouble going to 1955 and then back to 2015. It is also very likely that Mr.Fusion is a relatively common appliance in 2015 evidenced by its design and signs of branding. Therefore 2015 Biff may be familiar with the device. Also, even if Biff needed to refuel, all Mr. Fusion takes is garbage to fuel it. Therefore, he likely had no problems finding garbage in 1955. In the re-shooting of the DeLorean's departure from 1985 that took place in order to incorporate Elizabeth Shue, "less old" Biff witnessed the departure and may have known to accelerate if not the precise speed he needed to reach.

The shirt that doc's wearing is a bit of foreshadowing by the film makers. The shirt mimicks what will happen in the third movie when Doc and Marty try to catch the train on horses' to take Marty back to 1985. So basically the shirt Doc is wearing is telling the viewer Doc and Marty's future in the past.

By the end of the first movie, Marty is just one week older. He entered 1955 on November 5th at 6:00 A.M., and then left November 12th at 10:04 P.M., which totals one week, 16 hours, four minutes. Marty re-enters the timeline 10 minutes earlier, thus making him one week, 16 hours, 14 minutes older than he was on October 26th, 1985, at 1:24 A.M. when he left. At the start of Back to the Future Part II, Marty, Jennifer, and Doc travel to October 21st, 2015, spending less than a day there. Then they go back to the alternate 1985 for just a few hours. We know that the two events take about a day for Marty and Doc from the dialog upon their arrival in 1955, "This is heavy, Doc. It's like I was just here yesterday." "You were here yesterday, Marty. You were!" Marty spends all of November 12th getting the book back. So, at the end of this movie, Marty has aged two more days.