History Main / PlotArchaeology

** In ''VideoGame/CriminalCaseMysteriesOfThePast'', [[AristocratsAreEvil the Rochester family's corruption]] and evasion of justice are brought up during Elysium Fields, the game's second district, as the ArcVillain ends up being a KarmaHoudini for his actions due to how powerful and influential his family is, but nothing is really resolved and the Rochesters mostly disappear from the story when you leave Elysium Fields. Twenty-four cases later, though, you reach Wolf Street, the game's seventh district and where the Rochesters officially become the main focus of the story for the next three arcs as you attempt to dismantle their corruption machine and stronghold over the city.

* At one point in ''WesternAnimation/SupermanTheAnimatedSeries,'' ComicBook/{{Brainiac}} blasts former partner ComicBook/LexLuthor with a ray that (like many instances of FamilyFriendlyFirearms) doesn't seem to hurt him much for what appeared to be intended as a killshot. Much much much later in ''WesternAnimation/JusticeLeagueUnlimited,'' we find that [[spoiler: ''that's because it actually wasn't.'' Brainy put his data inside Lex in case he was destroyed, and this backup of himself was now needed. Enter... Brainithor!]] ThePowersThatBe have said that they'd actually planned it the day they wrote the zapping scene, they just didn't have the right opportunity to use it for a long, long time. Lucky for them the DCAU lasted long enough to do it.

Do not confuse with [[AdventurerArchaeologist an archaeology plot.]]

** The main villain of "[[Recap/DoctorWhoS20E1ArcOfInfinity Arc of Infinity]]" is revealed to be Omega, who first appeared in "[[Recap/DoctorWhoS10E1TheThreeDoctors The Three Doctors]]", which aired ten years previously. This kick-started the twentieth season, which featured a returning element from the series' past.

** Foundation X were set up early on to be the {{Overarching Villain}}s of the second half of franchise's Heisei era, but were gradually forgotten after ''Series/KamenRiderFourze''. They would eventually return in a special for ''Series/KamenRiderExAid'', before serving as the BigBad of the {{crossover}} film between ''Ex-Aid'' and ''Series/KamenRiderBuild''.

** The Third Summers Brother. In 1993, Mr Sinister casually refer to Cyclops having "brothers", then corrects himself. This arc got aborted when Fabian Nicieza left the X-titles before he could reveal the third brother was Adam-X, the X-Treme. Over the next ten years, the concept was never referred to. (Robert Weinberg thought it was Apocalypse, but also left the book before he could say so). In 2004 Creator/ChrisClaremont suddenly brought it up again, and revealed it was Gambit, but that was in an AlternateContinuity. Then, in 2006, Scott and Alex finally meet Gabriel Summers, aka Vulcan. Unfortunately, Vulcan's backstory makes it impossible that Sinister could have known about him in order to make that casual offhand reference. Fans now wonder if there's a fourth Summers brother. Or perhaps even more than that; Sinister didn't mention a number, just that Cyclops has more than just the one brother he was aware of at the time.

* In the first season of ''Series/{{Heroes}}'', Hiro falls in love with a waitress named Charlie. It turns out she has a brain tumor and is going to die. Hiro [[spoiler:accepts that he can't save her, gets some CharacterDevelopment, and the plot moves on. Several seasons later, Hiro regrets that he didn't save her, and the arc focuses on her again as Hiro goes back in time to try and save her, but she gets kidnapped and held hostage by the BigBad.]]
* ''Series/NewsRadio'' had a storyline where Lisa decided she wanted to have a baby with Dave. This went on for a few episodes, then was quietly dropped. In a later episode the same season, there is a brief conversation about how the moment had passed. The writers hated continuing story lines, which the network continually tried to force on the show.

* ''Series/StargateAtlantis'': Stardrives were mentioned very briefly in an early episode and didn't become massively important until the finale three seasons later.

* In ''Series/{{Sliders}},'' the Kromaggs were a season two MonsterOfTheWeek who got one mention in season three. Then comes a ChannelHop... and their return as the franchise BigBad.

* On ''Series/BabylonFive'', much of Captain Sheridan's character arc in Season 2 centers on [[DeathByOriginStory the death of his wife]] and how he needs to let it go and move on with his life. Fast forward to the end of Season 3, and [[spoiler: Anna Sheridan shows up on B5, with a message for her husband from the Shadows.]]
* On ''Series/{{CSINY}}'', serial killer Shane Casey is introduced in episode 3.04, "Hung Out to Dry," and eludes capture for a while, but is caught and sent to a maximum security prison by the end of the season. He escapes late in season 6 and wreaks havoc again before being killed during a home invasion in the cliffhanger-finale / season 7 premiere.
* ''Series/VeronicaMars'': Veronica's rape is seemingly resolved in Season 1. [[spoiler:She learns that she and Duncan had consensual sex while under the mutual influence of roofies, which left her with no memory, and Duncan left and never mentioned it to her because he believed she was his half-sister (which she wasn't).]] It then came back in a big way in Season 2, with the revelation that [[spoiler:while she and Duncan had had consensual sex, Cassidy/Beaver Casablancas was lying about never having hurt Veronica - ''he'' raped her while she was unconscious that same night.]]
* ''Franchise/KamenRider'': The {{crossover}} movies are particularly fond of digging up old plot points and expanding on them.
** The ''Film/KamenRiderZX'' special was originally made to promote a TV series that never took off. It's plot would be brought back however when the villains from it return in ''Film/HeiseiRiderVsShowaRiderKamenRiderWarsFeaturingSuperSentai'' and try to resurrect [[LegionOfDoom an army of past villains]] to take over the world.
** The penultimate episode of the original ''Series/KamenRider'' introduced a minor character by the name of Doctor D. While he disappears not long after making his first appearance, he becomes relevant in the leadup to the ''Film/SuperHeroTaisenGPKamenRider3'' film, where his research is used by the villains to enact their TimeTravel plan.
** Foundation X were set up early on to be the {{Overarching Villain}}s of the second half of franchise's Heisei era, but were gradually forgotten after ''Series/KamenRiderFourze''. They would eventually return in a special for ''Series/KamenRiderExAid'', before serving as the BigBad of the {{crossover}} film between ''Ex-Aid'' and ''Series/KamenRiderBuild''.

* In the ''Literature/AnitaBlake'' series, the events of book 11 resulted in the vampire serial killing group Anita was after not actually getting caught. Fans bitched and complained when the next few books didn't mention it at all, and then in Book 17 LKH went back to it and we finally get to confront the BigBad. A few other loose threads from that were also left hanging in that book and the one right after it which are still waiting to be picked back up though.

Compare TheBusCameBack and SequelEpisode. Contrast AbortedArc, which this may be a later result of. See also UnCanceled, PostScriptSeason, and {{Continuation}}.

* Creator/DCComics usually make this with certain events in its history, reviving old (and more than finished) issues and collections just for the event's sake. Some examples are seen in the ''ComicBook/BlackestNight'' event where all the historical tiles of DC had one more number (i.e. if a collection finished on issue 405, the ''BN Special'' is the 406) and even some {{crossover}}s with actual characters as seen in events like ''ComicBook/ZeroHour'' and ''ComicBook/{{Convergence}}''.

''Manga/MyHeroAcademia'': During the Forest Training arc, it's revealed there is a traitor within UA acting as a mole to aid All For One. The point proceeded to be ignored for several, real-time years and there was even misinformation that the creator just forgot. Finally, Chapter 336 shows the traitor is [[spoiler:Aoyama, who was forced to work for AFO and quickly sides with the heroes upon discovery, feeling crushing guilt for all he's done]].

[[folder:Film ]]

* ''Film/StarTrekIITheWrathOfKhan'' was all about digging up a one-episode villain from the first season of the original series and answering Kirk's question about what would happen with the "seed" that the Enterprise crew planted.

* In ''Series/StarTrekTheNextGeneration'', Wesley Crusher is built up as being a very special person, and it is suggested that he would do something remarkable, eventually. Then he was phased out of the show, and was gone for something like three seasons. Come the final season, the CreatorsPet returns, and the plot arc completes itself.

* At one point in ''WesternAnimation/SupermanTheAnimatedSeries,'' ComicBook/{{Brainiac}} blasts former partner ComicBook/LexLuthor with a ray that (like many instances of FamilyFriendlyFirearms) doesn't seem to hurt him much for what appeared to be intended as a killshot. Much much much later in ''WesternAnimation/JusticeLeagueUnlimited,'' we find that [[spoiler: ''that's because it actually wasn't.'' Brainy put his data inside Lex in case he was destroyed, and this backup of himself was now needed. Enter... [[FanNickname Brainithor!]]]] ThePowersThatBe have said that they'd actually planned it the day they wrote the zapping scene, they just didn't have the right opportunity to use it for a long, long time. Lucky for them the DCAU lasted long enough to do it.

* ''WesternAnimation/AvatarTheLastAirbender'': one early episode introduces Bato from Katara and Sokka's father Hakoda's fleet, and suggests the kids can meet up with the fleet. When this fails, no further attempts are made to meet up with Hakoda or the fleet until the end of the second season.

* At one point, ''Series/UglyBetty'' had a plot arc about Amanda trying to discover the identity of her biological father. After a few episode, the plot disappeared with no resolution. In the show's GrandFinale, Amanda finds her father, out of the blue and completely by accident.

[[folder:Manga & Anime ]]

* In ''{{LightNovel/Durarara}}'', the slasher is mentioned early on a couple times but not addressed until much later.
%%* In ''Manga/{{Bleach}}'', a number of plots are left unfinished in the wake of newer developments, only to be brought up much later in the story.

[[/folder]]

In short, what distinguishes this from similar tropes is that it's not just a one-episode reappearance, either as a ShoutOut or a full-fledged SequelEpisode (which may be considered a SubTrope). Do not confuse with [[AdventurerArchaeologist an archaeology plot.]]

A plot arc that was incomplete and forgotten, and then suddenly brought back out of the blue to continue the plot arc itself. This is distinct from the ContinuityCavalcade and ContinuityPorn tropes in that it's not just a ShoutOut type situation - the plot arc is resumed, essentially where it left off.

* ''Manga/MoriartyThePatriot'': Moran's DayInTheLimelight arc, ''The Man with the Golden Army'' resolves with Moran's backstory dealt with and himself able to move on fully devoted to William, and all seems well. Until ''The Adventure of the Empty Hearts'' brings up The Great Game from his and Moneypenny's adventures back in India from that arc, and the plot is explicitly mentioned as a part of the same nefarious plot.