MovieChat Forums > Back to the Future Part II (1989) Discussion > Plot hole

Plot hole

posted 4 months ago by fani (431)
1 reply | jump to latest

So Marty and Doc go tor Jennifer's future home in 2015 to get her back because cops have dropped her home.

Biff follows them in a taxi after overhearing talk about time machine.

There are several plot holes and illogical events that happen

* How does Biff know the DeLorean is the time machine?
* How does Biff know he should go to 1955 and not 1985 or any other point in time?
* Why would Doc and Marty not lock the DeLorean especially in that neighborhood
* why would the DeLorean not have a driving key all cars had back then?

And bigger ones
* How does Biff know how the time machine works? and especially that he needs to get to 88mph?

And mainly
* Doc establishes many times that the DeLorean must be recharged with special fusion power to generate the 1.21 Jigga (Giga) watts of power after each time travel use else it won't activate time circuits that needed plutonium in the first movie. And he had a crate full he stole from the Libyans and almost forgot to take it the first time in the first movie opening.
So Biff should not even be able to time travel at all. And especially return from 1955.
Doc immediately after this even puts things into fusion machine to get time travel working again.

This is a fantastic trilogy but has plot holes.

[–] HellFire (561) 2 months ago

"How does Biff know the Delorean is the time machine"

Because he witnessed it fly off and disappear in 1985 when he came out of the McFly house.

"How does Biff know he should go to 1955"

He doesn't have to. He wants to so he can give himself the book when he's 17 or 18, start understanding the results are constantly accurate so that he's ready to start betting as soon as he turns 21.

"Why would Doc and Marty not lock the Delorean"

Doc told Marty to stay with the Delorean so there was no need to. It's just that Marty ended up getting really nosey and started to walk down the street which is when old Biff stole it.

"How does Biff know how the time machine works"

An idiot could figure it out. You have the panel screens and numbers to dial. It's obvious you just key in your destination. Again, he saw the Delorean take off in 1985 so he knows he needs to pick up speed. He just gradually does that until he time travels. It could've taken him a few hours or even days to figure it out as long as he returns just after he left, then Marty and Doc won't see him.

And for your last paragraph, the Delorean doesn't need plutonium anymore after the original film. Doc got it converted in 2015 so that it runs on rubbish that you put into Mr. Fusion.