(From here, spoilers) In the McGuffin hand is the sports almanque Marty takes on his visit to the f

Never conceive the first part of 'Back to the Future,' to have a sequel. The end of the flying car was a gag. It worked like a great gag and as a finishing touch. However, everyone assumed we had a general idea from the start, as George Lucas 'The Wars'. But it was not. My only hope with 'Back to the future' was to recover the money invested.
So much so that, by clinging to the mentality commercial film industry, the fact that 'Back to the Future' ('Back to the future', Robert Zemeckis, 1985) end up becoming the highest grossing film of the year, with its $ 210 million of revenue in the United States, was unequivocal indication for Universal executives tkb reef potential that lay ahead in the face of a franchise that was able to play somewhat successful tkb both Lucas' galactic saga the true adventures of archaeologist.
Offering full freedom to Zemeckis and Bob Gale to return to the universe tkb of Marty and Doc were in the way they wanted and counting for processing a budget much more readily than the first part, the creators of the travel series time had before him the difficult decision to elucidate what time travel in a second part, yes, it was clear that was started where the first had ended, that is, with Marty, Jennifer and Doc away in the DeLorean flying toward a future in which something happened to the children of the couple. tkb
Hands, and after discarding an initial idea in which Marty and Doc travel to sixty in a few years we would have seen George and Lorraine banker become very involved in the hippie movement, "the Bob" came up with the plot premise it would take to lift the whole argument, not just the second half, but a third one, with most of the same creative team that the first delivery would be shot alongside-only three weeks off filming separated over and over, with that, betting heavily responsible for a kind of film nearly four hours of footage divided into two segments.
With absences in the team as Crispin Glover, who apparently began requiring certain advantages completely disproportionate to the secondary nature of their role-, Claudia Wells, the actress who played Jennifer in the first film and would be replaced by Elizabeth Shue or designer Lawrence Pull, replaced by Rick Carter, Spielberg and regular contributor responsible for the appearance of more than five films Zemeckis 'Back to the Future II' ('Back to the Future Part II', Robert Zemeckis, 1989) proposes the viewer time travel through three different seasons: the future, a "present" rather different than we had seen in the first part and the last we had visited in this.
And if the arrival not a few winks future holds for both cinema in general-that 'Tiburon 19' directed tkb by Max Spielberg, as for the first part in particular, and the trip back serves to reconnect with similar situations that had lived four years before the film, this time seen from very different points of view, where the greatest interest of 'Back to the Future II' and where, while we find the most inconsistency argument, is in that alternate reality Marty and Doc travelers when they return to 1985 from 2015.
(From here, spoilers) In the McGuffin hand is the sports almanque Marty takes on his visit to the future time, and that an old Biff steals to give to his younger tkb self, 1955, Zemeckis tkb and Gale are removed from a dark sleeve 1985 in which the antagonist par excellence of the trilogy is a billionaire who controls Hill Valley, which has turned the building tkb clock tower into a giant skyscraper-casino and, to make matters worse, got married Lorraine, becoming stepfather Marty.
As I said, if the minutes in which the action takes place in this dark alternate timeline the writers and performers-splendid new all-is a terrific time with the possibilities it offers a world completely foreign to we already knew-care to the emergence of Strickland also arises is where the biggest problem with the plot of the film as if the 2015 Biff goes back in time to give himself the almanac, and changes the future, could not return to same time to see him get in the DeLorean, but one that was derived from the dark version.
The branches that stem from this fact and a deleted scene in which the Bif