History Main / TimelineAlteringMacGuffin

* Ocurrs in "Mr. Was" where the main character previously wrapped a sandwhich in newspaper. This newspaper had stocks from the future on it when he went to the past. The man who later became his grandfather found this paper and used it to get rich.

** One of the comics actually referenced that event when various representatives were at Admiral Kirk's trial including one from that planet, with the only result being that the representative simply gives it back to McCoy after saying how he'd left it behind.

* ''Series/StarTrekVoyager'' has a 29th Century timeship that was sent back to 1967. Interestingly, the 29th century technology helps create the "holoemitter" The Doctor uses for the rest of the series, so the timeship was a TimelineAlteringMacGuffin to the 24th Century as well.

*** [[spoiler:Scotty had not only already invented the formula, but had tested his theory before. ItWentWrong, leading to his assignment at the remote outpost we see, but this could be part of the AlternateUniverse. Spock only shows Scotty a ''revised'' version of his theory, bringing his own discovery earlier into the timeline.]]

* ''WesternAnimation/BigBuyAndRustyTheBoyRobot'': When BGY-11 was accidentally sent to the past, it was found by English soldiers who learned how to control it. They renamed it "Iron Jack" and used it to stop TheAmericanRevolution. Because nobody knew everything needed for its maintenance, it eventually blew up but the damage was done. As a result of this, nobody developed BGY-11 or anything else that could have stopped the alien invasion BGY-11 did at the beginning of the series in the original timeline. Dwayne Hunter and Rusty then had to travel back in time to recover it and set history right.

* ''BigBuyAndRustyTheBoyRobot'': When BGY-11 was accidentally sent to the past, it was found by English soldiers who learned how to control it. They renamed it "Iron Jack" and used it to stop TheAmericanRevolution. Because nobody knew everything needed for its maintenance, it eventually blew up but the damage was done. As a result of this, nobody developed BGY-11 or anything else that could have stopped the alien invasion BGY-11 did at the beginning of the series in the original timeline. Dwayne Hunter and Rusty then had to travel back in time to recover it and set history right.

* In ''SDGundamGGeneration DS'', the cast of ''Anime/TurnAGundam'' travels back in time to try and prevent the apocalyptic "Dark History" from coming to pass. Unfortunately, [[MobileSuitGundam Gihren]] [[CompleteMonster Zabi]] gets his hands on the Dark History data, which allows him to produce an army of super-mecha equipped with knockoffs of the Turn A's GrayGoo weapon.

* ''WesternAnimation/JusticeLeague'' villain Vandal Savage sends a laptop containing the history of WorldWarII to himself in the 1930s. With his advanced knowledge, WW2!Savage easily outwits the Allied forces, deposes Hitler and sets his sights on world domination. The present!league minus Batman (given RippleEffectProofMemory by being protected by Green Lantern's power when it was sent back) must go back in time to prevent this.

* In ''TransformersRescueBots'', Doc Greene's robot, Dither, ends up being one of these. [[OlderThanTheyLook Doctor Morocco]] gets his hands on Dither in 1939, which leads to a BadFuture.

* The ''[[SixteenThirtyTwo 1632]]'' series is about a small town from West Virginia sent back to the central Germany during the ThirtyYearsWar, so almost every object in the town is a TimelineAlteringMacGuffin. A stupid king of England got his hands on history books and began executing people who would be responsible for the English Revolution years before it happened, thus earning some enemies years early and [[spoiler: causing some of his allies to join forces with Cromwell]]. Cardinal Richelieu got his hands on history books, realized a problem with his current policy that he hadn't noticed before, started an impressive {{Xanatos Gambit}}, and [[CrowningMomentOfAwesome purchased America]]. And everyone is trying to reverse engineer 20th-century weapons. The storyline follows the altered timeline so it's impossible to say exactly how this will change things, but a safe guess would be "a lot".

The former Trope Namer Gray's Sports Almanac is from ''BackToTheFuture Part II''.

* The former Trope Namer was Gray's Sports Almanac in ''BackToTheFuture Part II'', which allowed Biff Tannen to become wealthy through using the information from the 2015 Gray's Sports Almanac that his future self brought to him in 1955 to make bets on the outcomes of sporting events.

The former Trope Namer Gray's Sports Almanac is from ''BackToTheFuture Part II''. (Whenever referring to this trope, be sure to pronounce it like Marty did when he confronted Biff in the hot tub ("[[PunctuatedForEmphasis Gray's... Sports... Almanac]]"). [[RuleOfFun It's fun]]!)

*** It should be noted that [[spoiler:Scotty had not only already invented the formula, but had tested his theory before. ItWentWrong, leading to his assignment at the remote outpost we see, but this could be part of the AlternateUniverse. Spock only shows Scotty a ''revised'' version of his theory, basically bringing his own discovery earlier into the timeline.]]

** Of course the protagonists are GenreSavvy enough to realize what's going on, and go to great lengths to secure their remaining books. [[spoiler:One particularly nasty minor character who was selling history books to rival governments is told (in order to maintain his continued survival and freedom) to inform his customers that he will only sell copies because his supply is running low. The copies are loaded with deliberate misinformation. Thus the great Florida Gold Rush ensues...]]
* Done in Alfred Bester's ''Time and Third Avenue.'' A young lawyer accidentally gets a copy of the almanac from the far future year of 1985 and a timecop stops him before he opens it. The lawyer says all right, you can have the almanac: using it to speculate on stocks or bet on elections would be cheating, and I'm sure I can have a great career without cheating... only, I wish I could have some reassurance that the world won't end in a nuclear holocaust. So the timecop gives him a hundred dollar bill, one of the 1980 series. He can't spend it in his time, of course, but he feels that he's well paid [[spoiler: when he reads the name of the Secretary of the Treasury from the bill... and it's him.]]

* A non-time travel version occurs in the ''Series/StarTrekTheOriginalSeries'' episode "A Piece of the Action": A pre-Prime Directive starship 100 years prior had inadvertently left behind a book on Chicago gangs of the 1920s, which caused the civilization in question to develop into the original PlanetOfHats, with an entire culture based around 1920s gangsterism. After the crew has fixed the entire planet, [=McCoy=] leaves his communicator behind, alarming Kirk who worries that this trope will take effect. "In a few years they could be demanding a piece of ''our'' action!"

The former Trope Namer Gray's Sports Almanac is from ''BackToTheFuture Part II''. (Whenever referring to this trope, be sure to pronounce it like Marty did when he confronted Biff in the hot tub ("[[ThisIsSparta Gray's... Sports... Almanac]]"). [[RuleOfFun It's fun]]!)

* ''StarTrekVoyager'' has a 29th Century timeship that was sent back to 1967. Interestingly, the 29th century technology helps create the "holoemitter" The Doctor uses for the rest of the series, so the timeship was a TimelineAlteringMacGuffin to the 24th Century as well.

* In ''StarTrekEnterprise'', when [[spoiler:stranded]] in the 29th century, Archer finds a book about [[BigBad the Romulan Star Empire]]. Luckily, Daniels is there to stop him from reading it.

* In ''StarTrek IV'', Scotty teaches the 20th century plastic maker how to make "transparent aluminum", justifying it with the argument, "We know it was invented around this time, but we don't know the name of the man who invented it. It could have been him."

** The 2009 ''StarTrek'' film played with this trope [[spoiler:by a future Spock showing Scotty an equation that he would eventually create -- however earlier in the film the reason that future Spock is there is explicitly stated to be an AlternateUniverse, not a StableTimeLoop.]]

* A non-time travel version occurs in the ''StarTrekTheOriginalSeries'' episode "A Piece of the Action": A pre-Prime Directive starship 100 years prior had inadvertently left behind a book on Chicago gangs of the 1920s, which caused the civilization in question to develop into the original PlanetOfHats, with an entire culture based around 1920s gangsterism. After the crew has fixed the entire planet, [=McCoy=] leaves his communicator behind, alarming Kirk who worries that this trope will take effect. "In a few years they could be demanding a piece of ''our'' action!"

** The ''[[StarTrekDeepSpaceNine Deep Space Nine]]'' writers at one point considered doing an episode that revisits the planet and finds that all the inhabitants are now dressing up as Kirk and Spock. This episode was to be a Star Trek 30th anniversary celebration, and was dropped in favour of "Trials and Tribble-ations". Considering how good "Trials and Tribble-ations" turned out, they probably made the right choice. The concept was later picked up in a comic.

* Another non-time travel version is in ''{{Predator}}: Concrete Jungle''. The game starts in 1920s Chicago, where the Predator accidentally leaves some of his technology behind. Cut to modern-day, and the technology has become way advanced, with {{Hollywood Cyborg}}s and [[IWantMyJetpack flying cars and all that fun stuff.]]

** They also rely heavily on ambush; with surprise on their side they take out entire fleets in moments, but in a stand-up fight the Enterprise can hold her own by shooting down it's improvised torpedoes.

The former Trope Namer Gray's Sports Almanac is from ''BackToTheFuture Part II''. [[hottip:*: Whenever referring to this trope, be sure to pronounce it like Marty did when he confronted Biff in the hot tub ("[[ThisIsSparta Gray's... Sports... Almanac]]"). [[RuleOfFun It's fun]]!]]

* In ''Comicbook/{{Sandman}}'', people are digging up a bunch of those from an archaeological dig in Crete. Sadly [[spoiler: some of them are explosive.]]

** Ironically, Adam himself is at risk of becoming one. He has his own brain upgraded in the future, to interface with the computers of the time. Now whenever someone snaps their fingers near him a little port on his forehead opens up. The Doctor mentions that Adam has to lead a quiet life and not draw attention to himself, or he risks [[TheydCutYouUp being dissected]] for the future technology in his skull. At the end of the episode, his mother snaps his fingers while talking to him.

** Ironically, Adam himself is at risk of becoming one. He has his own brain upgraded in the future, to interface with the computers of the time. Now whenever someone snaps their fingers a little port on his forehead opens up. The Doctor mentions that Adam has to lead a quiet life and not draw attention to himself, or he risks [[TheydCutYouUp being dissected]] for the future technology in his skull.

* One episode of ''WesternAnimation/AmericanDad'' had Stan go back in time to prevent JaneFonda from ruining Christmas (in his opinion). A tape of disco's greatest hits is accidentally left behind, where it's discovered by the past version of Roger the Alien, who becomes insanely rich thanks to it.

** The nigh-unstoppable warship belonging to the villain is also an example. In its own time period it is merely a mining vessel. Its ability to [[spoiler: blow up planets]] is due to certain modifications, however.'

* The Trope Namer in ''BackToTheFuture Part II'', which allowed Biff Tannen to become wealthy through using the information from the 2015 Gray's Sports Almanac that his future self brought to him in 1955 to make bets on the outcomes of sporting events.

--> -- '''Vandal Savage''', ''JusticeLeague''

Essentially the reverse of the ButterflyOfDoom, the Timeline-Altering [=MacGuffin=] is a nondescript item from the future that, if left in the past, will bring about an AlternateTimeline. This can be something that contains information about the future, such as a history book, for instance. It could also be a future technology that [[GivingRadioToTheRomans someone in the past decides to reverse engineer]]. The item will probably become a MacGuffin pretty quickly.

* The "Whispered" of ''FullMetalPanic'' are privy to "[[BlackBox Black Technology]]" -- devices they should be unable to design for decades or even centuries. It's extended their ColdWar clear into the 21st century.

* In ''{{Sandman}}'', people are digging up a bunch of those from an archaeological dig in Crete. Sadly [[spoiler: some of them are explosive.]]

*** That's not so bad. Marty got to be THE rock star!

* The arm and CPU from the first ''{{Terminator}}'', left behind in the 1980's, brought about the rise of SKYNET. [[TimeyWimeyBall Well, sometimes.]] In any event, since the Terminator was sent back in time ''by'' SKYNET, this is also a StableTimeLoop...until it's broken by the destruction of the items in the second movie, which doesn't stop SKYNET from rising again in the third. Yeah, TimeyWimeyBall.
** It's justified. Although they destroy the ''original'' T-800's arm and CPU, the second T-800 leaves behind a ripped off arm in the machinery in which the T-1000 trapped him in the smelting plant.
** Not at all. There's certainly no trace of advanced AI in this arm. Skynet was meant to be invented anyway, it was only a matter of time. The CPU of the first Terminator improved human researches dramatically, causing the Judgement Day in 1997. The destruction of the second Terminator's CPU only postponed Skynet's creation.

*** TruthInTelevision - no really - [[http://www.physorg.com/news167925273.html and he wasn't even that far off]] for when...

* A non-time travel version occurs in the ''StarTrekTheOriginalSeries'' episode "A Piece of the Action": A pre-Prime Directive starship 100 years prior had inadvertently left behind a book on Chicago gangs of the 1920s, which caused the civilization in question to develop into the original PlanetOfHats, with an entire culture based around 1920s gangsterism.
** After the crew has fixed the entire planet, [=McCoy=] leaves his communicator behind, alarming Kirk who worries that this trope will take effect. "In a few years they could be demanding a piece of ''our'' action!"
*** One of the comics actually referenced that event when various representatives were at Admiral Kirk's trial including one from that planet, with the only result being that the representative simply gives it back to McCoy after saying how he'd left it behind.
*** The ''[[StarTrekDeepSpaceNine Deep Space Nine]]'' writers at one point considered doing an episode that revisits the planet and finds that all the inhabitants are now dressing up as Kirk and Spock. This episode was to be a Star Trek 30th anniversary celebration, and was dropped in favour of "Trials and Tribble-ations". Considering how good "Trials and Tribble-ations" turned out, they probably made the right choice. The concept was later picked up in a comic.
*** The 1989 tie-in book ''[[http://memory-alpha.org/wiki/The_Worlds_of_the_Federation The Worlds of the Federation]]'' had the same idea. When contact was re-established sometime around the Next Generation time period, the entire planet had restructured their society around TOS-era Starfleet and extrapolated enough technology to build a working starbase and apply for Federation membership.
*** The NES ''Star Trek: 25th Anniversary'' game starts out with the Enterprise being pulled into unknown space by a wormhole. When they finally reach Federation space again, they figure out that the wormhole was a side effect of the gangster planet blowing itself up. The last mission requires you to go back in time to retrieve the communicator and prevent the explosion/wormhole.
*** There was also the Next Generation comic issue "A Piece of Reaction" which follows the same plot (more or less).

*** And in the ExpandedUniverse novels, specifically ''StarTrekDestiny'', this does come back to bite them.

** Ironically, Adam himself is at risk of becoming one. He has his own brain upgraded in the future, to interface with the computers of the time. Now whenever someone snaps their fingers a little port on his forehead opens up. The Doctor mentions that Adam has to lead a quiet life and not draw attention to himself, or he risks being dissected for the future technology in his skull.

* While not exactly a mundane item from the future, the titular ''[[TheElderScrolls Elder Scrolls]]'' serve a similar function. They were written by a god and contain records of history: All that has happened, all that will happen (usually in the form of "If X happens, then Y and Z will happen, in that order"). They are extremely hard to read, causing blindness if read too often, but they are used by the emperor to secure the wellbeing of his empire, guiding his course of action.
** In ''Skyrim'' the player gets to read one themselves. If used near a temporal rift it lets them see an important piece of the past; used anywhere else it strikes them blind.

* ''JusticeLeague'' villain Vandal Savage sends a laptop containing the history of WorldWarII to himself in the 1930s. With his advanced knowledge, WW2!Savage easily outwits the Allied forces, deposes Hitler and sets his sights on world domination. The present!league minus Batman (given RippleEffectProofMemory by being protected by Green Lantern's power when it was sent back) must go back in time to prevent this.

* The ''[[SixteenThirtyTwo 1632]]'' series is about a small town from West Virginia sent back to the central Germany during the ThirtyYearsWar, so almost every object in the town is a GraysSportsAlmanac. A stupid king of England got his hands on history books and began executing people who would be responsible for the English Revolution years before it happened, thus earning some enemies years early and [[spoiler: causing some of his allies to join forces with Cromwell]]. Cardinal Richelieu got his hands on history books, realized a problem with his current policy that he hadn't noticed before, started an impressive {{Xanatos Gambit}}, and [[CrowningMomentOfAwesome purchased America]]. And everyone is trying to reverse engineer 20th-century weapons. The storyline follows the altered timeline so it's impossible to say exactly how this will change things, but a safe guess would be "a lot".

* ''StarTrekVoyager'' has a 29th Century timeship that was sent back to 1967. Interestingly, the 29th century technology helps create the "holoemitter" The Doctor uses for the rest of the series, so the timeship was a GraysSportsAlmanac to the 24th Century as well.

* In the ''Series/DoctorWho'' [[BigFinishDoctorWho audio drama]] "Colditz", it's discovered that their accidental appearance at Colditz Castle goes horribly wrong, and Nazis from the 1960s reveal they got the ''TARDIS''. The twist is that [[spoiler: the GraysSportsAlmanac isn't the TARDIS, but a CD Player which leads to the Nazis getting hold of the TARDIS]].