Resolved: There were no time travel plot holes in any of the three "Back to the Future" films.

Plot Taking up where the previous film left off, Marty McFly, "Doc" Brown and Jennifer Parker arrive in 2015. Doc tranquilizes Jennifer, who is not necessary for his plan, explaining that he brought her along only because she saw the time machine. Doc explains that Marty's son is about to be approached by Griff Tannen, Biff's grandson, and his gang, who will ask him to take part in a robbery. According to Doc, this event leads to the ruin of the entire McFly family. Marty impersonates his future son and tells Griff he will not join the robbery, leading to a hoverboard chase that damages the nearby courthouse. Griff and his gang are arrested and the planned robbery never occurs. Before meeting up with Doc, Marty notices a sports almanac in a store window which lists sports statistics through the year 2000. Imagining the potential for financial gain in 1985, Marty buys the book. Doc discovers the almanac and throws it away, chiding Marty for his plan. Meanwhile, Jennifer, still tranquilized, is found by the police, mistaken for her future self after thumbprint identification, and taken to her future home. Hiding in a closet, she witnesses the Marty of 2015 being fired from his job he is caught in an illegal scheme that his colleague, Douglas J. Needles, goaded him into joining. Doc finds Jennifer and sneaks her out of the house. Biff's casino hotel in 1985A.While Doc is rescuing Jennifer, the old-aged Biff of 2015 recovers the discarded sports almanac and steals the De Lorean. He returns the car to 2015 just as Marty and Doc prepare to leave for their own time. Upon arrival in 1985, Marty and Doc find that Hill Valley has become a dilapidated, crime-ridden slum lorded over by a middle-aged Biff, who is now immeasurably rich and powerful thanks to decades of successful sports betting. He has also married Marty's widowed mother, Lorraine, after secretly killing her husband George. Doc deduces that the Biff of 2015 must have given the almanac to his younger self sometime in the past. Marty confronts Biff and finds out that he received the almanac on November 12, 1955, the date on which the climax of the previous film took place. Marty and Doc travel back to 1955 to prevent Biff from getting the almanac. Marty eventually manages to steal the book from the 1955 Biff and burns it, restoring history to its proper course. As Doc attempts to land the De Lorean to pick Marty up, the car is struck by lightning, causing it to disappear. A few seconds later a Western Union delivery man appears with a letter, which he explains was sent seventy years ago with the explicit instructions that it be delivered to Marty "at this exact location, at this exact minute, November 12, 1955." Marty tears open the letter, which is from Doc, explaining that he is now trapped in 1885. Marty runs to the clock tower to find the Doc of 1955, just as lighting strikes as depicted in Part I. Seeing Marty, who he has just sent back to 1985, Doc faints to a cliffhanger of "to be concluded..." appearing onscreen. This is followed by a teaser trailer to Back to the Future Part III before the credits. [edit] Cast Michael J. Fox as Marty McFly Sr., Marty McFly Jr. and Marlene McFly Christopher Lloyd as Dr. Emmett L. Brown (aka Doc Brown) Lea Thompson as Lorraine Baines (McFly/Tannen) Thomas F. Wilson as Biff Tannen and Griff Tannen Elisabeth Shue as Jennifer Parker (McFly) James Tolkan as Mr. Strickland Jeffrey Weissman and Crispin Glover (BTTF1 footage) as George McFly Billy Zane as Match Casey Siemaszko as 3-D J.J. Cohen as Skinhead The characters of George McFly and Jennifer Parker were played by actors different from those of the original film, requiring that some previous scenes be reshot. [edit] Production The original script for Back to the Future Part II had Marty and Doc Brown go back to 1967 instead of 1955, had Mr. Fusion destroyed, with Marty and Doc Brown having to fly the De Lorean over the Grand Canyon. [edit] Replacement of Crispin Glover As Bob Gale states in the DVD commentary, actor Crispin Glover was asked to reprise the role of George McFly in this film. Glover indicated interest, but demanded a salary the producers felt was unreasonable. Glover reportedly refused to budge, so he was dropped from the picture. Glover later insisted in a 1992 interview on The Howard Stern Show that he and Zemeckis had had some "creative disagreements" over the character, and felt that the director simply wanted an actor who was more pliable. He also said that the salary offered was "really low" (reportedly around $50,000), and that he was certain they never really wanted him back.[citation needed] In the BTTF FAQ, Gale and Zemeckis state that Glover was uninterested in doing the sequels and was asking for the same salary as Michael J. Fox, and therefore was written out of the story.[1] As a result, the filmmakers found inventive ways of avoiding showing the character's face in the movie, despite the fact that George McFly was in certain key scenes and dialog. During all scenes in which the George McFly character appears in both this film and Back to the Future Part III, he is played by Jeffrey Weissman and seen wearing sunglasses, from the back, upside-down, or out of focus in the background. This was to prevent audiences from realizing that George McFly was played by a different actor. However, producers also recycled unused footage from the original Back to the Future that included Crispin Glover's portrayal of George McFly. Glover sued Universal for compensation, on grounds that his contract for the first film did not allow subsequent uses of his portrayal of George McFly in new films. The day before the lawsuit went before a judge, Universal quietly settled the case, paying the actor an undisclosed sum. Glover would not reveal the amount during his Howard Stern Show appearance, but did suggest the real reason for the settlement was that Universal was reluctant to "open up their accounting books to the public" during the trial. The Screen Actors Guild later rewrote their rules regarding the derivative use of actors' works in films or TV series, requiring the studios and networks to give appropriate payment and credit to the actors. [edit] Replacement of Claudia Wells Claudia Wells' scene at the end of Back to the Future (top) was reshot with Elisabeth Shue for the beginning of Back to the Future Part II (bottom).Claudia Wells, who had played Marty McFly's girlfriend Jennifer Parker in the original Back to the Future, reportedly had personal problems and opted to drop out of acting in 1987.[citation needed] The producers reluctantly cast Elisabeth Shue for the part, which required reshooting the closing scenes of Back to the Future for the beginning of Back to the Future Part II. A comparison of both films reveals that Shue appears to be considerably older than Wells (and slightly taller than Michael J. Fox). It was more than a decade before Claudia Wells returned to Hollywood, with a starring role in the 1996 independent film Still Waters Burn. She is one of the few actors not to make an appearance during the 2002 "behind the scenes" documentaries on the Back to the Future trilogy documentaries on DVD. [edit] Rumors and urban legends Marty, wearing self-fitting sneakers, riding a Hoverboard in 2015As a joke, Director Robert Zemeckis said during an interview that the hoverboards (flying skateboards) used in the movie were real. A surprising number of people thought he was telling the truth and demanded them at toy stores. After the release of Part III, Zemeckis had the opportunity to explain in another interview that all of the flying scenes were accomplished by a variety of special effects techniques. There was even a high demand for the Nike Sportshoes Marty wears with automatic shoe-laces, which fans thought to be real. After the Florida Marlins beat the Cleveland Indians in the 1997 World Series, and