October 21 is the 294th day of the year.
- 2015, Wednesday:
- Timeline 1
- Timeline 2
- 4:29pm: Doc Brown, Marty McFly, and Jennifer Parker arrive in the future from 1985 in the DeLorean time machine.
- Doc reveals to Marty about his kids and the trouble they would endure if Marty does not stop them.
- Marty subs for his future son Marty Jr.
- Marty encounters Griff Tannen and turns down his proposal to rob the substation.
- Griff's gang chased Marty around the Courthouse Square.
- The gang is jailed for crashing into the Courthouse and changes the original history.
- Marty meets Terry and becomes inspired to purchase the Grays Sports Almanac.
- Doc releases Einstein from a suspended animation kennel.
- Doc discovers the almanac and disposes of it.
- Jennifer, assumed to be old Jennifer is taken to Hilldale.
- Old Biff Tannen overhears their conversation, grabs the almanac and follows Doc and Marty to Hilldale in a taxi.
- Doc and Marty rescue Jennifer.
- Old Biff steals the DeLorean and travels to November 12, 1955
- Old Biff returns and due to changing history, begins to fade away from existence.
- Doc and Marty leave for 1985, only to later find out that it has become 1985-A.
- Timeline 3
- 3:29pm: One hour before he originally brought Jennifer and Marty to 2015, Doc Brown turns on a self tracking video camera in an attempt to catch a space time correction on video. In order to stop a nuclear holocaust from occurring in 2045, he departs in the DeLorean time machine to an undisclosed time to prevent the invention of the food hydrator, self lacing shoes, the hoverboard, and the Mr. Fusion home energy reactor.
- Timeline 4
- The camera catches the hydrator, self lacing shoes, hoverboard, and the Mr Fusion being erased from time. His mission was a success, and scientific advancement has occurred differently than it had before. The only technology that was shown to exist in the new timeline was tablet computers, the internet, self tracking video cameras, and digital versions of newspapers.
- Doc realizes that, although his mission was a success, things didn't go to plan as he inadvertently kept the Quantum Mind Jar, when he meant to leave it behind in 2075.
- Doc Brown from another timeline arrives, and also declares his mission a success. Both versions of Doc are surprised that they have arrived at the same place at the same time.
- 2045, Saturday: It is the 30th anniversary of the arrest of Griff Tannen and his gang, for crashing their hoverboards into the Hill Valley Courthouse. Griff Tannen originally inadvertently caused a nuclear holocaust when he attempted his revenge, but that timeline was rewritten when Emmett Brown prevented the invention of the Mr. Fusion.
- 2014, Tuesday: Hendo announces it has been working on a prototype hoverboard which can hover approximately one inch off the ground using magnetic fields and specially-lined copper floors.
- 2015, Wednesday:
- Back to the Future Day celebrated worldwide on the date of Doc and Marty's arrival in the future, now present.
- The first issue of IDW's Back to the Future: Untold Tales and Alternate Timelines comic is released.
- Worldwide theatrical re-release of Back to the Future Part II, and in some theaters, all three films.
- Release of the Back to the Future trilogy on Blu-ray and DVD, including a new short film Doc Brown Saves the World, and Back to the Future: The Animated Series on DVD.
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