Arc Welding

For almost a full season, the plucky folks who help those in need have defeated Monster of the Week after Monster of the Week, protected the space-time continuum from invading aliens, stopped an Antimatter explosion from removing North America from the face of the planet, and saved the President.

Now, however, they are vexed by someone who seems to know their strengths, their weaknesses, and everything in between. They're outmaneuvered, outnumbered, and outsmarted. The season ends with the villain gloating over them, saying their most dangerous tasks up to that point have simply been tests he has engineered.

The Arc Welder cometh.

Arc Welding is a form of Continuity Creep that occurs when a series which has heretofore been episodic retcons itself so that it's all linked in a Story Arc. The most common approach to Arc Welding is when an antagonist, hidden up to that point, is shown to be responsible for all the major threats the protagonists have faced thus far.

Alternatively, several seemingly disconnected arcs might be revealed to part of a larger Myth Arc. This is rarer, possibly because it's harder to do well, and any works that attempt it may risk being cancelled before they can make the big reveal or retcon.

Arc welding is different from Story Arc or Myth Arc because it is always retroactive; or, at the very least, the work doesn't make it clear that there is one of these at play until much latter. Similarly to the Cerebus Retcon, without Word of God, it can sometimes be hard to tell if the emergence of an overarching story was a later decision made because the creators wanted to try something new and/or realized their work had an underlying theme they can take advantage of, or if it was planned from the beginning and all the episodic content was meant to ease the audience into The Reveal. In the absence of confirmation, Arc Welding is YMMV.

Compare Canon Welding, which ties together different series, and Innocuously Important Episode, which retroactively ties a seemingly unrelated event into an existing Story Arc. See also Meta Origin, Patchwork Story, Plotline Crossover, Hyperlink Story. Under the right circumstances, Greater-Scope Villain and Greater-Scope Paragon can both come into play as well, especially if the events of seemingly unrelated parts of a story are later revealed to have been caused by or tied to a specific villain or specific hero.

Contrast Not So Episodic, which is similar, but lacks the Retcon.

Has nothing to do with welding metal using arcing electricity. For info on that, go here. For a minigame on that, go to Metroid Prime 3: Corruption.

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Examples:

• Comic Books

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Anime and Manga

• Bleach: Was the plot up to Big Bad Aizen's defeat a self-contained arc unconnected to the Thousand Year Blood War? Hell no! Aizen's deeply involved in many of the events that set up the War, but the Final Arc's Big Bad was secretly involved in many earlier events as well. While the first arc appears to be a protracted chess game between Aizen and Urahara, the final arc answers the question of who had provided the chessboard. The final arc connects events as disparate as the death of Ichigo's mother, Rukia's execution, Ichigo's substitute shinigami badge, Aizen's hollowfication experiments, Ryuuken's hatred of Quincies, and more. Word of God has indicated that the arc welding actually occurred at the end of the Soul Society arc when Tite Kubo realized how to end the story on the basis of what he'd written up until that point. This discredited a fan theory that the length of the Arrancar Arc was a result of Kubo stalling because he hadn't figured out how to end the plotline. Thus far, Rewrite Retcons have been avoided, although several events (most particularly Masaki's death) have had to be Revisioned.
• Danganronpa 3 ties together the plot arcs of Makoto Naegi and the 78th class of Hope's Peak Academy, Hajime Hinata and the 77th class, and Komaru Naegi and the events in Towa City.
• Every subplot in Excel♡Saga, which were all Played for Laughs, actually got tied together in the surprisingly serious finale.
• Happened quite a lot in Fist of the North Star. A few volumes after Kenshiro's Token Motivational Nemesis Shin was killed off, it is revealed that the reason why he turned on Kenshiro in the first place was because Ken's stepbrother Jagi (a later villain) persuaded him. Later, Shin is revealed to have only faced Kenshiro to build upon the Gosha Stars' lie that Yuria died as a result of her suicide attempt, so that Raoh won't be able to find her.
• This is pretty much the whole reason the Mobile Suit Crossbone Gundam manga exists: without it, Mobile Suit Gundam F91 and Mobile Suit Victory Gundam come off as two unconnected stories that just happen to be set in the UC timeline. With it, the stories are tied together into a larger overarching narrative with the Jupiter Empire and its aristocratic oligarchical philosophy as The Man Behind the Man of both the anime series' Big Bads.
• Naruto:
  • A minor example: A Filler episode of the original series revealed that Mizuki attempted to steal the kinjutsu scroll on Orochimaru's orders. This revelation occurred around episode 160 or so, and Mizuki stole the scroll in episode 1.
  • A major example: Tobi is largely responsible for/connected to the origins of Naruto (he unleashed the Nine-Tailed Fox on the Hidden Leaf Village, forcing the Fourth Hokage to seal it in Naruto), Sasuke (he helped Itachi with the Uchiha massacre), the messed-up state of the Hidden Mist Village in Part 1 (he was mind-controlling its leader), etc.
  • Kakashi Gaiden was originally just a short prequel arc detailing the origin story of Kakashi. Years later, it turned out to also be the beginning of the origin story for Tobi himself.
  • The Sage of the Six Paths is first mentioned as being the founder of the ninja arts (and the first guy with the Rinnegan), but is later revealed to be both the ancestor of the Senju, Uchiha, and Uzumaki clans, and the guy who split the almighty Ten-Tailed Beast into the nine different Tailed Beasts that exist today, creating the MOON in the whole process.
• Pokémon Adventures tends to do this:
  • Both good guys and bad unexpectedly show up in later arcs with gambits ahoy, but FireRed and LeafGreen and Emerald take the cake. FRLG was a result of all the previous arcs while Emerald was a direct consequence of FRLG. For reference, Emerald was the sixth arc, and Pokemon in general rarely bothers with continuing plots across multiple games/series/whatever.
  • Volumes 29 (climax of Emerald) and 38 (climax of Diamond and Pearl, beginning of Platinum) brought together and resolved so many plot lines from different arcs to the point that the "Holy Shit!" Quotient shot up to high levels.
• Pretty Cure All Stars DX 3 did the same thing the manga Sailor Moon did with Black Hole. Though since DX 3 is mostly non-canon to the series they're connected to, it kinda really doesn't count.
• In Sailor Moon DiC tried to do this to all the bad guys that appeared during the second season. Then later Naoko Takeuchi did this with the bad guy Chaos at the end of the manga who was supposedly responsible for the appearance of all the previous Big Bads.
• The Speed Racer episode "The Trick Race," which is the third to last episode of the series, introduces a gang of spies who say that various other criminals from previous episodes, including "Gang of Assassins" and "The Dangerous Witness," were all members of their organization.
• Tenjho Tenge. Every bad thing that ever happened to anyone turned out to be the work of the protagonist's dad. Even the stuff that happened centuries ago.
• Yu-Gi-Oh! GX has this with season four, where it is revealed that the release of the Sacred Beasts, the Light of Destruction, and Yubel's schemes were all used by the final Big Bad Darkness for...something.
• Yu-Gi-Oh! 5Ds, the villains of the first major story arc are Roman Godwin and his brother Rex, who are revealed to be responsible for the Zero Reverse incident that severed Domino City in two. The next season revealed Roman's turn to evil was engineered by the Ancient Conspiracy Yliaster as a plot to destroy Domino City with Zero Reverse. After the three leaders of Yliaster were defeated, the founder of the organization, Z-one, appeared as the final antagonist of the series, picking up the trio's plans to destroy Domino. The final arc also revealed that Paradox, the antagonist of Yu-Gi-Oh!: Bonds Beyond Time, was also an agent of Yliaster working on a secondary plan in that film.
• Chapter 170 of YuYu Hakusho confirms that everything that happened in the series was a result of King Enma's actions. He created falsified reports of demon crimes in the human realm, let evil demons into the human realm, and even brainwashed innocent demons for his Spirit Detectives to finish off, increasing Enma's reputation within Spirit World, since the Spirit Detectives were under his command. This gave Enma the authority to erect a barrier between the three realms, as supposed demon "crimes" would create the illusion that this was a righteous act, and not totalitarian, since the spirit energy unused by humans was a valuable resource to the Spirit World.

Fan Works

• Calvin & Hobbes: The Series:
  • Dr. Brainstorm claims to have done this in order to build the Doom Satellite.
  • Played straight in "Our Solemn Hour", where Holographic Retro reveals he was behind the power outage in "Surge", the return of Electro in "Part Three", the "save Aankor" plan in "Invasion", and the "Freaky Friday" Flip in "Bodyswap" (though he intended it to erase their memories).
• The Dear Sweetie Belle Continuity: The series originated as disparate stories (Rarity's letter to Sweetie Belle, Luna and Shining Armor's affair, the romantic setups of Morning Glory) which the author realized fit together well. He also attempted to tie in another of his stories regarding an AU where Luna took over, but that didn't work out so well.
• Facing the Future Series: It's revealed in A Family Thing that Vlad was behind Vortex and Nocturne's escape from Observant custody, and their subsequent actions, in Hearts and Minds.
• Flaihhsam s'Spahkh does a fair amount of this. Spock's appearance on Romulus in the TNG two-parter "Unification" is referred to, and he has since become the official ambassador to Romulus, foreshadowing his relationship with the Romulans in the Star Trek (2009) movie, and spearheads the effort by the Federation to get the cloaking device for the USS Defiant following the clusterfuck with the USS Odyssey in "The Jem'Hadar".
• Guardians, Wizards, and Kung-Fu Fighters:
  • This is doe with a couple of secondary antagonists from Jackie Chan Adventures. Recurring crime boss Bartholomew Chang and oneshot relic thief Vanessa Barone are presented as the heads of the Asian and European branches of the Dark Hand, respectfully, despite neither having a known connection to the organization in canon.
  • In his Start of Darkness chapter, it's revealed that Daolon Wong gained the mouths in his hands (and the ability to extend his life by using them to drain the life-force of others) by cutting a deal with the Jiangshi which the Chans fought in a canon episode.
• Harmony's Warriors does this to tie together the stories based on the X-Men movies and those based on the Marvel Cinematic Universe: Gustav, the Big Bad of X-Questrians: First Class, is revealed in Captain Equestria to have been a member of HYDRA back in the day, serving as Hoity Toity/Red Skull's Dragon.
• Infinity Crisis has more than one exemple of this.
  • Another Side of the Glimpses takes multiple franchises/characters and welds them together.
    • The MCU Deadpool is stated to be the same one that traveled with the Deadpool Corps (with Word of God also saying that elements of the Joe Kelly & Daniel Way runs and several mini-series are canon to his backstory).
    • Chapter 3 combines, by the way of mentioned events and characters (even if unnamed), several (if not all) of the major continuities of the Sonic the Hedgehog franchise.
    • Chapter 9 takes the official welding that Mr. Mxyztplk got since Superman Reborn and carries it over in IC. Later, Chapter 11 of Counterpart Conferences would confirm it and expand it further.
  • A big arc-welding character introduced in the series is The Wild Card, who is later revealed to be The Pighead, one of the authors. Her presence and meddling with the timelines is used to bring together several previous events (the X-Men and the Thunderbolts existing in the MCU, She-Hulk and the Fantastic Four gaining their powers, Benny Blacktooth bring an enemy of Mei Ling's family...) and explain that it was her doing all along.
  • The Ultra-Humanite, who was responsable for ordering a hit on Supergirl (which succeeded) on Fourth of July, is later revealed to also subtly influence the local Peter Parker into taking interest in Curt Connors' research.
  • In Chapter 3 of The Pilot & the Meddler Hit the Road, the appearences of an unnamed, hoodie-wearing person in the previous chapters of the same series are connected to Pighead's employment in the Hazbin Hotel by revealing that both persons are actually one and the same but also Pighead's future self who came back to the past, wishing to atone for her past misdeeds.
• The Lion King Adventures:
  • Death, the Big Bad of Series 3, reveals in Darkness Falls that he was directly responsible for everything that happened to Simba and his friends throughout the series.
  • The End reveals that Series 5 Big Bad The Writer is the Unseen Evil who created every other villain in the series, all for no other reason than his own amusement.
• Pony POV Series:
  • A single chapter ("The Connection") manages to tie together every arc, story and alternate universe together into a single story of redemption, salvation, hope and change. Specifically, when the alicorn version of Twilight from the Dark World finishes saving it, she then creates an alternate timeline by blowing herself up (twice) into four beings — Shining Armor, whose presence would prevent Twilight from creating the Dark World by keeping her own canon from melting down, and the three Interviewers who've been recording this story and guiding the heroes the whole time.
• Pony POV Series Chaos Verse: The Big Bad Nightmare Phobia is revealed to be behind nearly every problem the Mane Six have for most of the show up to "Luna Eclipsed" (excluding Discord) by manipulating their emotions to make them act in self-destructive ways.
• Reimagined Enterprise puts together many different disconnected references and plot points from Star Trek canon into new stories.
• It's very common in the fandom for Spyro the Dragon to combine The Legend of Spyro continuity with the original series. Oftentimes, it's used to bring characters from the older games into the new ones, especially the other dragons. Other times, it's just used to attempt to bring the two alternate plotlines together.

Films — Live-Action

• Howling VII: New Moon Rising tried to do this, and actually did an admirable job. Unfortunately, the director chose to have the exposition delivered in massive Info Dumps. The Agony Booth had a field day with it:
  If you do, put this story in several five-minute segments. We wouldn't want to exhaust the poor Inspector, would we?
• James Bond: Spectre establishes that Nebulous Evil Organization Spectre was behind the Quantum group from Casino Royale and Quantum of Solace, as well as Raoul Silva from Skyfall, and the arc ends with No Time to Die. Behind-the-scenes, Quantum was created as a Suspiciously Similar Substitute for Spectre, as Spectre's film rights were legally unavailable to Eon Productions for decades.
• In Scream 3, the killer, Roman, reveals that he was responsible for the events of the first movie and the second movie, being the one who inspired Billy and later his mother to start killing.
• The Young Indiana Jones made-for-TV film "Treasure of the Peacock's Eye" revolves around Indy and Remy attempting to find a fabled diamond known as "The Peacock's Eye", which supposedly once belonged to Alexander the Great; they ultimately fail to find it, with the ending leaving it ambiguous whether the diamond actually exists. But sometime after the film first aired, George Lucas stated that the diamond from the opening sequence of Indiana Jones and the Temple of Doom is the Peacock's Eye, meaning that the two stories were connected all along.

Literature

• Awake in the Night Land, which is set in the universe of William Hope Hodgson's The Night Land, linked this book to The House on the Borderland by stating that the titular house is the entrance to the House of Silence of The Night Land, but in the past.
• The Dark Tower series is a major Arc Welding project for the works of Stephen King, bringing together multiple previously introduced concepts and characters for a Saving the World plot of epic proportions. It had long been established that many of King's works took place in the same continuity (the towns of Derry and Castle Rock were recurring locations, and there were a few characters that appeared in multiple works), but their plots had generally stayed independent from one another before that point. The Dark Tower reveals that all of his works coexist with each other, even when they seem to take place in different universes—because his world is a multiverse where multiple parallel Earths exist simultaneously, and certain gifted characters can travel from one parallel world to another. To elaborate:
  • The vampires from 'Salem's Lot and the "Low Men" from "Low Men in Yellow Coats" are both part of a massive army commanded by the mysterious Crimson King from Insomnia. Randall Flagg from The Stand and The Eyes of The Dragon is the Crimson King's Dragon, serving as his emissary on Earth.
  • The psychics Ted Brautigan (from "Low Men in Yellow Coats") and Dinky Earnshaw (from "Everything's Eventual") are two of many psychics being systematically tracked down and recruited by the Crimson King's agents so that they can harness their abilities to bring the Dark Tower crashing down. Though never stated, it's presumed that characters like Danny Torrance from The Shining and Carrie White from Carrie are similar such psychics, and that their abilities could also bring down the Tower if so utilized.
  • The mystical "Turtle" entity from It is "Maturin", one of several Guardian spirits that exists to protect the Dark Tower. Each world has its own Guardian (in Roland Deschain's world, for example, it's a bear called "Shardik"), and they all oppose the Crimson King in his quest to destroy reality.
  • Project Arrowhead from The Mist is one of the few agencies ever to successfully discover the nature of the Multiverse, and their theory about the existence of parallel worlds was 100% true. Also, the titular mist was a "thinny", a weak spot in the barrier between parallel worlds that characteristically emits white fog and high-pitched keening noises that can drive a person insane. And the monsters from the mist were creatures from "Todash", the primordial darkness between worlds from which the Crimson King was born.
  • The world of The Stand, which becomes a post-apocalyptic wasteland in the wake of a disastrous plague, is one of many parallel worlds that exists in the Multiverse. Randall Flagg was trying to conquer that world in the name of the Crimson King, and he wanted to build his own new civilization atop the ashes so that his new subjects could be added to the Crimson King's army.
• Doctor Who Expanded Universe:
  • The Doctor Who Missing Adventures novel Venusian Lullaby takes a lot of the throwaway one-liners the Third Doctor used to make about his adventures on Venus (that the Venusians sing lullabies, play hopscotch, etc.) and makes a coherent alien race out of them (living about a billion years in the past, when Venus might have been habitable). They're radially symmetrical and move by hopping. Oddly, no mention is made of the oft-referenced "Venusian Aikido" (at least by that name), nor how he might have learned it from such odd creatures.
  • The Past Doctor Adventures novel Divided Loyalties establishes that the Doctor was part of a clique in the Prydonian Academy on Gallifrey with the other renegades featured in the original series (the Master, the Monk, the War Chief, the Rani and Drax), Vansell (introduced in the Big Finish audio drama "The Sirens of Time" earlier that year), two new characters (Jelpax and Millenia), and Rallon, who is revealed to have been posessed by the Celestial Toymaker, who used his body in the First Doctor serial by that name.
  • Original Sin establishes that Tobias Vaughn from "The Invasion" was responsible for various advanced technologies that plagued the Third Doctor, and also created the glitterguns from "Revenge of the Cybermen".
  • John Peel's Eighth Doctor novel War of the Daleks does this with the final four Dalek serials of the classic series ("Destiny", "Resurrection", "Revelation" and "Remembrance of the Daleks"), creating a single overarching plot which was promptly ignored by every Who writer since.
  • The Doctor: His Lives and Times (a reference book mostly written as an in-universe Scrapbook Story) ties stories together to provide more of a narrative for each Doctor's adventures. Most blatantly, the Seventh Doctor section suggests that Fenric's manipulation wasn't just responsible for "Iceworld and Nemesis", but for almost everything that happened to that incarnation.
• According to J. R. R. Tolkien, he didn't really hit on how to make The Hobbit and The Lord of the Rings fit together until he realized that the Necromancer (an entirely offscreen villain Gandalf was mentioned as going off to fight to get him out of the picture) could have been an alternate identity of Sauron. He also rereleased portions of The Hobbit to turn the One Ring from a nifty little magic item to an Artifact of Doom, justified as Bilbo now telling the true story after prompting from Gandalf.
• All 7 other of the Incarnations of Immortality series, encompassing epic acts by Death, Time, Fate, War, Nature, God and the Devil had this trope. In the last novel in the series, Under a Velvet Cloak, all of these acts are only minor compared to Nox's (the Incarnation of Night/Secrets) actions (whose actions choose which universes live or die).
• The Larry Niven Known Space stories develop a bad case of this later on, as the hugely successful Ringworld degenerated into increasingly complex and incomprehensible attempts to produce a Unified Field Theory of Everything.
• Arthur C. Clarke's Rendezvous with Rama, Rama II and The Space Odyssey Series.
• Lemony Snicket: The Unauthorized Autobiography played this for laughs. Most of the book consists of explaining how everything that had happened up to that point in the series was related to the VFD in various ludicrous ways.
• The first Noob novel did this to some episodes of the original webseries, making it part of the Horizon storyline. When an episode of Season 1 needed to show a character doing Fetch Quest (which happened three or four times out of twenty often stand-alone episodes) the Quest Giver always happened to be In the Hood and dressed in Black Cloak, something that could easily be normal for the game and/or due to No Budget. The first novel, chronologically set after the first season, reveals that the black cloak is actually a trademark for a group that is after the Dismantled MacGuffin central to the first novel; some of the pieces were used as decoration for random objects that they sometimes couldn't go get themselves without attracting attention, hence the fetch quests.
• Sherlock Holmes: It was revealed, in the first of the two stories by Arthur Conan Doyle to directly feature Moriarty, that the master villain had been involved in several of Holmes' cases before, but had simply never been mentioned until then.
• This sort of thing is quite common in Star Trek Novel 'Verse books:
  • The Star Trek: The Next Generation novel Q & A has every Q-episode of TNG, as well as the Negative Space Wedgie encountered in the episode "Parallels", as being part of Q's long term plan to prepare Picard for meeting the beings that sit in judgement over the universe, and convince them it's worth saving. Except "Q-Pid". That one he just did for the hell of it.
  • Similarly, the Star Trek: The Next Generation novel Q-Squared implies that almost all the temporal anomalies encountered by Picard and his crew were also the work of Q - and goes on the add a relationship between Q and one-shot villain Trelane from Star Trek: The Original Series too.
  • Peter David is quite fond of this. In Vendetta, the planet-killer from The Doomsday Machine turns out to have been engineered by a long-dead race as their final revenge against the Borg.
  • Star Trek: Forged in Fire ties Sulu's captaincy of the Excelsior (as seen in The Undiscovered Country and explored further in Star Trek: The Lost Era) to the Blood Oath plot from the eponymous episode of Star Trek: Deep Space Nine. In other words, Sulu's story arc is now made part of the backstory of Curzon Dax and the Klingon trio of Kor, Kang and Koloth. The novel also ties in the Klingon Forehead arc, from Star Trek: Enterprise and Star Trek: Vanguard.
  • The Star Trek: Typhon Pact novel Paths of Disharmony links the Star Trek: Vanguard story arc to those of the Star Trek: Deep Space Nine Relaunch and the post-Star Trek: Destiny line, making it all relevant to the current events of the novel.
  • A rather pleasing example in the Star Trek: Voyager Relaunch with the exploits of Kahless, retroactively linking the novel line's Klingon saga to the relaunch in interesting ways. In Star Trek: A Time to..., Kahless had replaced himself with a hologram (equipped with a mobile emitter) and wandered off to Cygnet IV, supposedly to "do whatever (he) felt like". It was also a test, allowing him to give his usual Hurricane of Aphorisms when the ruse was discovered. In the Star Trek: Voyager Relaunch, though, it's revealed why he was on Cygnet IV specifically. The secret headquarters of the qawHaq'hoch are located there, and he's keeping the plates spinning in the plan to keep Miral (B'Elanna and Tom's daughter) safe from the fanatics trying to kill her. Further, the mobile emitter for his holographic replacement was created by B'Elanna herself.
  • Any Christopher L. Bennett novel in the line (Ex Machina, The Buried Age, Watching The Clock) is like this. It sometimes borders on Continuity Lockout, but never crosses the line.
  • The Q Continuum trilogy ties together three previously unconnected malevolent energy beings from the original series and movies along with the Galactic Barrier (yes, one of them is "God" from Star Trek V), and as an extension explains why proximity to the barrier resulted in the development of telekinetic powers and personality shift in the original series pilot.
    • We also get a bit of patching for one Plot Hole with Star Trek V. The barrier was at the edge of the galaxy in the show, and nigh impossible to get through. In the movie, it was in the middle of the galaxy and they managed to get in easily enough. Well, it turns out there's two barriers. One is keeping something bad in, the other is keeping something much, MUCH worse out.
• Many Star Wars Legends sources tie in many of Palpatine's and especially Thrawn's actions as being to prepare the galaxy for the Yuuzhan Vong invasion. The degree to which this is accepted by fans varies— it's pretty much considered canon for Thrawn's motivation, but most see Palpatine as just using it as an excuse.
  • Jacen Solo's Face–Heel Turn in Legacy of the Force was tied to the Big Bad Abeloth in Fate of the Jedi, though the exact connection was unclear. It's later revealed that while Jacen initially became evil to prevent a Bad Future, Abeloth's defeat is the last step needed to fully avert it.
  • Another example is Cade Skywalker's unique abilities in Star Wars: Legacy. His ability to sense vulnerable fractures has been tied to Mace Windu's sense for more metaphorical "shatterpoints" from the book of the same name, and his ability to heal serious injuries and death using the Dark Side is uncannily close to what Palpatine claimed Darth Plagueis could do in Revenge of the Sith. And considering that other sources hint that Plagueis created Anakin, it may be connected to that too... though that was Jossed in the Darth Plagueis novel. Anakin was created as a backlash against Plagueis's machinations.
  • Back to the subject of Abeloth, the final Fate of the Jedi novel reveals that she's connected to the Son, the Daughter, and the Father, the living embodiments of the Force first seen in Star Wars: The Clone Wars. She was a mortal woman who became a sort of stepmother in that family, but was corrupted by trying to become immortal like them. Furthermore, the Son and Daughter then directed the Killiks to build Centerpoint Station, a mysterious ancient superweapon introduced in The Corellian Trilogy, which in turn constructed the Maw, a black hole cluster featured in the Jedi Academy Trilogy, as a prison for Abeloth.
    • The same novel also has the Jedi Council speculating that Anakin Skywalker's refusal to take the Father's place had unbalanced the Force, which thus caused almost every other conflict since then.
• Some Warrior Cats books have melded two subplots together to make their story through use of a retcon.
  • Crookedstar's Promise introduces the Dark Forest to the past and shows it influencing the events of book as early as Fire and Ice through use of Crookedstar's story.
  • Yellowfang's Secret makes it so that SkyClan is directly responsible for the rise of Brokenstar, even though they had died out years before his birth.
• Ender's Game was originally followed by a number of sequels featuring Ender in the far future. The author later returned to the time period of the original novel by writing Ender's Shadow, a P.O.V. Sequel written from the perspective of Bean, one of Ender's friends. This was then followed by a number of Shadow novels taking place immediately after Ender's Game and Ender's Shadow. These two sub-series can be read completely independently from one another. However, later books start to get more interwoven, starting with Ender in Exile, a book set between Ender's Game and its original sequel Speaker for the Dead picking up an unresolved plot thread from the Shadow series. The two series became fully welded with the release of The Last Shadow, a chronologically final novel that acts as a finale for both sub-series.

Live-Action TV

• Graem Bauer and the "Bluetooth Group" in 24. The cabal of influential businessmen in the fifth season ordering Christopher Henderson et al. to do their dirty jobs was initially planned to be a shadowy group whose true motives were never explained (and they had no connection whatsoever to Jack or his past). In the sixth season, the previously unnamed head of this group was revealed to "Graem Bauer", and it was explained that he was responsible for most of the government's shady activities going all the way back to the fourth season (when Walt Cummings tried to have Jack killed). Graem is then revealed to be The Man Behind the Man, as his (and Jack's) father Philip shows up and murders him in his very first appearance.
  • Season 7 does it again, revealing the season's Big Bad, Alan Wilson, to have been behind even the Bauers' involvement, and the ultimate authority over the Season 5 conspiracy, being head of a powerful group that had been manipulating events for some time and remained at large at the end of the season. Then the storyline disappeared without a trace.
    • The arc technically got resolved with a Hand Wave in Season 8. It is mentioned that Alan Wilson’s entire group got discovered and arrested offscreen after the end of Season 7. Quite the anticlimactic end to such a supposedly powerful group.
• As part of the showrunners of Alias' attempts to course-correct after the debacle that was the series' third season, several elements from those episodes, such as Sloane's Omnifam enterprise and seasonal bad guy group The Covenant, were brought back and retconned into being parts of season four Big Bad Elena Derevko's master plan.
• One of the more explicitly identified examples of Arc Welding comes from Angel's fourth season, where Skip notes that everything that's happened to Angel and company for a very long time — Angel's ensouling, Cordelia's ascension, Fred's being trapped in Pylea, Lorne's banishment from Pylea — were all part of a Gambit Roulette. (It's known that this was all one big retcon because it wouldn't have worked without Charisma Carpenter's real-life pregnancy.)
  • A smaller version then happened in the next and final season: faced with Executive Meddling to be more episodic without any arcs, after finding out the show would be canceled anyway, Joss Whedon spent the last two episodes revealing that many of the villains over the season were part of a group called the Circle of the Black Thorn, then having the heroes kill them all.
• Battlestar Galactica (2003) did this extensively in its second half, due to a bad case of Writing by the Seat of Your Pants which stacked up. Creator Ron D. Moore later admitted that despite the show's initial dependence on meticulously plotted storyarcs, he hadn't actually planned out anything for the show beyond the end of the second season (various ideas like "another Battlestar also survived" or "what if they find a habitable planet that isn't Earth"? had been exhausted). The result was that with a bunch of disparate plotlines that he hadn't planned out, he desperately tried to retroactively weld them all together as related. For example, he admitted he had no idea why the much-hyped Hybrid child Hera was important, let alone how it related to the rest of the main plots, until he was writing the series finale itself. At the 2009 Paley Center post-finale panel (videos are on youtube of this), you can see Moore give his bizarre self-justification that he is fully capable of retroactively welding unrelated storyarcs together in a way that works. Needless to say, critics and reviewers were disenchanted as the show wore on.
• The Blacklist:
  • From the start, it was clear that Reddington only sent the FBI after people on the Blacklist as part of a larger plan, but it's not until the end of season 1, in the two-part "Berlin" episode, that we start to see what that plan is and exactly how the various Blacklisters fit into it.
  • "The Director, Conclusion" finally puts together all the hints and pieces of Red's plan throughout the first half of Season 3 to undermine the Cabal enough that he can exonerate the framed Keen, and take down the Director.
  • "Mr. Gregory Devry" reveals the existence of Shell Island Retreat, a gathering and alliance of the leaders of the world's most powerful criminal organizations. Aside from revealing Reddington himself as a member, several past Blacklisters are mentioned as having been involved before being taken down.
  • The Season 5 finale, "Sutton Ross", pieces togethers hints and clues scattered throughout the entire series up to that point for The Reveal that the man calling himself Raymond Reddington is in fact a fake pulling a Dead Person Impersonation.
  • Despite airing years after the Cabal Story Arc ended, the Season 6 episode "Minister D" wraps up a few dangling threads from it, and shows how they tie together into the larger Myth Arc. Specifically, it's confirmed that Katarina Rostova was an agent of the Cabal in addition to her work for the KGB, and that when Reddington came into possession of the Fulcrum, she helped the Cabal frame him for the treason that sent him on the run and hired the Red we know to steal his identity after his death in order to further ruin his name.
  • "Bastien Moreau: Conclusion" spells out exactly how the chain of Blacklisters from the first half of Season 6 are all linked together in Red's plan to expose a Government Conspiracy in exchange for clemency from his looming death sentence.
• In season two, Charmed (1998) established that the girls' mother, Patty, had had a Forbidden Romance with her Whitelighter, Sam. At the time, this was mostly to create a parallel to Piper and Leo's relationship. However, when a fourth sister needed to be introduced two seasons later, making her half-Whitelighter provided a handy explanation for why she needed to be hidden away until now.
• Chuck welded arcs on top of arcs. About midway through the first season everything that happened up to that point was revealed to largely be the result of a CIA splinter group known as FULCRUM attempting to steal the Intersect. By late in Season 2, Chuck has begun to speculate that many one-shot villains earlier in the first season such as Laszlo were actually connected to the Intersect project and FULCRUM. The Season 2 finale reveals that Fulcrum was part of a larger organization called the Ring. The middle of Season 3 reveals that the Ring's direct involvement goes back much further, and that another one-shot villain from Season 2 was actually working for them. When Season 4 rolls around, you learn that yet another one-shot villain from Season 2 was actually working for new series big bad Volkoff Industries, and that the entire history of the Intersect project itself was directly connected to Volkoff himself. Finally in Season 5 you learn that rogue CIA agent Quinn was quite literally behind EVERYTHING—Fulcrum, the Ring, and Volkoff Industries—out of his desire to get revenge on Chuck for "stealing" the Intersect from him.
• Doctor Who:
  • There was a bit of Arc Welding near the end of its original run, when Ace's involvement with the Doctor between "Dragonfire" and "The Curse of Fenric" (eight multi-part stories over three seasons by that point) was revealed to be part of Fenric's Batman Gambit to trap the Doctor (moral of the story: don't try a Batman Gambit against a Chessmaster). It also provided a bit of disappointment for Classic Who fans when the series returned and "Bad Wolf" turned out not to be a returned Fenric.
  • Between the Classic and revival series, the Time War, a cataclysmic war between the Daleks and the Time Lords, annihilated both races for good with the exception of the Doctor. The series eventually connects this event to the Fourth Doctor story "Genesis of the Daleks", where the Doctor attempted a genocide of the species but failed (which has no serious effects on the Classic series's overarching plot save for introducing Davros) — reimagining the event as the Time Lords firing the first shot in the war. Similarly, "Terror of the Zygons" is retconned to also be related to the Time War in "Day of the Doctor" as the Zygons' home planet is stated to be an early casualty of the Time War, driving them to invade Earth and claim it as a new home.
  • In Series 5 of the new series, the startling lack of historical commentary about a big freaking Cyberking stomping around Victorian London is retconned to have been another casualty of the cracks in time.
  • "The Time of the Doctor", the Eleventh Doctor's Grand Finale, concludes virtually all major ongoing plots (the cracks in time, the explosion of the TARDIS, the First Question, etc.) by tying them into the Ninth and Tenth Doctor Time War Myth Arc.
  • In Clara's first appearance in Series 7, "The Bells of Saint John", she offhandedly mentions she got the TARDIS phone number from a woman in a shop who told her it was a help line. Flashforward to the Series 8 premiere, "Deep Breath", where a mysterious ad in a paper reunites Clara and the recently regenerated Twelfth Doctor, after which he brings up the phone incident again, pointing out that someone seems to want them together. Flashforward again to the season finale, "Death in Heaven", where it's revealed that that woman was Missy, who brought Clara and the Doctor together as part of her larger overall scheme against the Doctor.
• A similar event occurred in Firefly, another Joss Whedon show. Although the Reavers and River's torture at the hands of the Alliance are introduced in the pilot episode, the Serenity movie later ret-cons them to being linked together. Now, instead of being a group of bloodthirsty savages as a parallel to the American Indians depicted in pulp Westerns, they are analagous to the Infected from 28 Days Later, and the reason that River is being so strongly hunted by the Alliance is that she knows secrets like this.
• Kaizoku Sentai Gokaiger episode 40, which not only turns the Gokaigers' Early-Bird Cameo (a Big-Lipped Alligator Moment during the Goseiger/Shinkenger Reunion Show) a canon event, but also ties into the team's quest of Gotta Catch Them All.
• In the old Kamen Rider series, many an evil organization was ruled by a guy called the "[insert this year's evil organization name] Great Leader," always voiced by veteran voice actor Gorō Naya. Welding comes in with the later seasons having the new [Organization] Great Leader often say "oh, yeah, I was behind them all, and those other organizations from the last couple of series I wasn't in too!" Not only were all of Naya's "Great Leaders" made one character, with the final enemy of Black RX voiced by Naya as well, it's theorized that every pre-hiatus Kamen Rider villain ever is either the Great leader himself or one of his pawns.
  • As for the modern era, he appears in teamups now and again, first voiced by Naya up until his death, and then replaced by Tomokazu Seki, though he doesn't take credit for seasons he wasn't in. However, the Non-Serial Movie of Faiz gave the Big Bad three Man Behind the Man figures, one being played by Naya. This in a series that also has people being turned into monsters. Though far from canon, there's a real case to be made for the Great Leader being behind that series.
  • The more recent series have Foundation X playing the same part: Double, OOO and Fourze all had them involved behind the scenes. The "Foundation X Trilogy" culminated in a film where they're finally the Big Bad instead of just behind the Big Bad... but the film's villain Lem Kannagi was a rogue member and his defeat was no setback to the organization. They're perfectly capable of saying "Oh, did you think [insert your favorite new villain here] did it alone?" about any series after them (except Gaim, perhaps.) On top of that, Kannagi's final form was a similarly-named homage to that of an old-school villain, and who were all the old-school villains created by, again?
• A great many of the episodes of the revival of The Outer Limits are retroactively revealed to take place in the same continuity. Unfortunately for continuity, several of those episodes are entirely contradictory. Some of them, however, are stated as taking place in Alternate Timelines.
• Power Rangers had two major examples of this:
  • Power Rangers in Space revealed that Dark Specter was behind everything that happened in the series to that point. Combining the narratives of all the previous seasons (Mighty Morphin, Zeo, Turbo, and In Space) into one greater arc.
  • Power Rangers Wild Force: The crossover with Power Rangers Time Force revealed that the Big Bad of that season gained his ability to pull weapons from his body from an encounter with three Orgs, the race of monsters the Wild Force team have been fighting.
  • In Power Rangers Ninja Storm it is revealed that each plot by the Big Bad Lothor was actually part of a very smart Batman Gambit.
• At the end of the first season of The Sopranos, Salvatore "Big Pussy" Bonpensiero has vanished. No one knows anything. The writers of the show were just going to let it go at that—people do, indeed, vanish with no explanation, though it's rare. However, when they heard how the fans were wondering what happened to him, they welded Pussy into the story of Jimmy Altieri's being The Mole, with him being a second one.
• Star Trek:
  • Two threads in the first two seasons of Deep Space Nine are Odo's search for information about where he came from, and the gradual reveal of a dangerous empire called the Dominion. The third season arc-welds these two threads together by revealing that Odo's people are the rulers of the Dominion—a decision the writers made between seasons 2 and 3.
  • The second season finale of Star Trek: Picard welds together the Supervisors (from the original-series episode "Assignment: Earth") and the Traveler (from The Next Generation). Y establishing that the Traveler is part of an organization that organized the Supervisors.
  • Various Time Travel adventures meant that Starfleet eventually developed a Time Police to try and maintain a Temporal Prime Directive, while they started as merely cataloging these instances and debriefing officers Star Trek: Voyager revealed the 29th century Starfleet has casual time travel and time scanners to do that job and would pop in to the contemporary time period. Star Trek: Enterprise then said by the 31st century there was a "Temporal Cold War" with numerous factions trying to manipulate the timeline to their advantage. This same event is hinted at in Star Trek: Strange New Worlds while Star Trek: Discovery reveals post "Temporal Cold War" in the 32nd century resulted in treaties banning development and use of time devices, while also saying the Krenim from Voyager was one of the factions and the Guardian of Forever from Star Trek: The Original Series was involved too.
• Stella used one frequent actor to set up an arc for the series.
• Arc Patching, if not Arc Welding, was done in Veronica Mars, when the season 2 bus bombing storyline wrapped up. The perpetrator was revealed to also have raped Veronica at Shelly Pomroy's party, a storyline thought to be wrapped up in season 1 as being not rape, but mutually drugged-up semi-consensual sex. This explained Veronica's chlamydia, despite her having only two (or, as The Reveal made plain, actually three) sexual partners and presumably using protection, the existence of which was used to paint Veronica as a slut and therefore untrustworthy in the trial of Aaron Echolls. The blatant illegality of delving into her medical records for some reason not resulting in a mistrial is another debate entirely.
• Whitechapel (TV Series) did this in its fourth season. Up until this point, the team had dealt with unrelated cases, but the fourth season not only introduces the existence of the supernatural, but posits that all the grisly crimes in Whitechapel are the work of a "provocateur" who goads all the murderers into committing their crimes.
• The X-Files did this in later seasons, with dormant alien DNA supposedly accounting for much of the apparently Earthbound paranormal activity Mulder and Scully investigated.

Music

• One of the few examples (perhaps the only one, seeing as concept albums are nowhere near as common as normal albums) occurring in Music: Between the Buried and Me do this with their Parallax storyline when it's revealed that Prospect 2 was the adult male that talked too much in "Lost Perfection", and that he was one of the three lovers of the woman in "Prequel to the Sequel".
• Marilyn Manson's Antichrist Superstar and Mechanical Animals were originally thought of as two separate concept albums, as they have different protagonists, plots, and points, plus the entire universe is destroyed at the end of Antichrist Superstar. With Holy Wood however, the Triptych was revealed, and the plot flows in reverse, from Holy Wood to Mechanical Animals to Antichrist Superstar. The protagonist of Holy Wood, Adam Kadmon, the first to rebel against Holy Wood, is the father of The Worm/Antichrist Superstar from, well, guess. Coma (who in the novel, only Chapter 10 of which was ever released, is the daughter of the leader of Holy Wood), is his mother, who after the suicide of Adam Kadmon, falls into rampant drug use and then the aliens Alpha and Omēga fall in love with her. When she herself dies in the song "Coma White", both lose hope, and the song "Irresponsible Hate Anthem", from Antichrist Superstar, is actually performed by Omēga, not The Worm, as proven by the three "live songs". The liner notes for Antichrist Superstar show that "Irresponsible Hate Anthem" was recorded live on Valentine's Day, 1997. However, the album came out in 1996. The liner notes again say this about "I Want To Disappear" off of Mechanical Animals, an album that came out in 1998, and the song was in fact not actually played at the real Valentine's Day, 1997 show. Finally, "Born Again" off of Holy Wood is also said to have been recorded on the same day. This song also was not played live, especially seeing as the album it's from came out in 2000. The albums tell the story of three characters. Holy Wood's Adam Kadmon fights the system, only to get brought into it and ultimately kill himself. Mechanical Animals' Alpha and Omēga are space alien rock stars, who crashed and were captured and enslaved. Alpha sings the emotional songs on the album, Omēga the vapid, drug songs, however turns against the system due to the death of Coma. The Worm, Adam and Coma's son, idolizes Omēga, and leads his own revolution against the system and wins, only to turn against his mindless, obsessive fans who worship him as a god, and in his rage becomes the Antichrist Superstar and destroys the universe, thus ending the Triptych.

Tabletop Games

• Up until the Invasion block of Magic: The Gathering, the storylines of the sets before were mostly Worldbuilding the plane of Dominaria. Then came the story revision, the Weatherlight set, and the Tempest block, which set up an ongoing storyline over the next twelve or so sets that would drastically change the way the game told stories, as well as cobble together all the previous sets into a sort of long-term storyline, which the arc would then deal with. It all came to a head in the Invasion block with the Big Bad and his cronies from the previous stories converging on Dominaria to overlay the artificial plane of Rath (introduced in the Tempest bllock) and give the Phyrexians (introduced back in Antiquities, the second-ever set) a new world to ravage.
  • Also, the problems that were dealt with in the Time Spiral block were said to have done things which were major in other blocks, like making the Emperor insane, which convinced him to steal a baby kami, which resulted in the Kami War which made up the Kamigawa block.
• The creators of the D&D setting Ravenloft retroactively Arc Welded its first six adventures together into the Grand Conjunction story arc, using a Vistani prophecy as solder.
• Arguably, the D&D settings Planescape and Spelljammer, both of which were specifically created to allow the numerous other settings of D&D to mix with each other.
• Sentinels of the Multiverse: Invoked by the writers. In the Letters Page podcast, the writers describe the publishing history of the Freedom Five as being originally a series of Monster of the Week one-shots where they were fighting robots or aliens each week. A later reboot took all those robots and retconned them as being Omnitron's drones, and took those aliens and retooled them as Voss's Gene-Bound legions.

Video Games

• The Artix Entertainment writers are so guilty of this trope it's not even funny. The most obvious example is their first and flagship game, AdventureQuest, which got so bad with this during the Devourer Saga that it was next to impossible for the userbase to keep track of who was responsible for what, or how X arc was supposed to fit into the wider Saga. The spin-off games are a lot better about this, but there's still some welding here and there that can cause crossed eyes.
• The Chzo Mythos tetralogy of games feature this; 5 Days a Stranger was originally a stand-alone game, as was its distant sequel, but the later titles tie them together to form an encompassing story arc. Appropriately, the major threat of the first two games (and an important story character in the other two) is an insane killer referred to as "The Welder" because of the mask he wears.
• The first four games in The Elder Scrolls series consist of largely unconnected stories set in the same world. However, the fifth game of the main series, Skyrim, does some Arc Welding which connects the overall stories in its main quest. Specifically, the destruction or removal of a various Cosmic Keystones and metaphysical "Towers" in the previous games herald the return of Alduin, the Big Bad Beast of the Apocalypse who was cast out of the stream of time in the past but prophesied to return.
• The four Downloadable Content packs of Fallout: New Vegas are part of a bigger storyline which lead to the confrontation of the player-character, The Courier with Ulysses, The Rival.
• Played With in Genshin Impact. There are side quests in the game called Hangout Events that have Multiple Endings, but the game never says with endings are canon. However, Beidou and Heizou both have branches in their Hangout Events that are connected to one another. In Beidou’s Hangout Event, it’s revealed that the Crux is involved in a smuggling operation to move goods out of Liyue, with Heizou’s Hangout Event revealing that the goods are sent to Watatsumi Island.
• In Guild Wars Nightfall, it's revealed that servants of Abaddon were responsible for driving the Charr into human lands in Tyria, leading to all the major background events of the Prophecies campaign; another servant led to the downfall of Shiro Tagachi, the Big Bad of Factions.
• King's Quest: Dahlia, Hagatha, Mannanan, and Lolotte all appeared to be generic evil wizards and wicked witches. But then, we hear that the Big Bad in King's Quest V is the "brother" of Hagatha and Mannanan and looking for revenge. Then King's Quest VI has a single, damning letter alluding to the "Brotherhood of the Black Cloak," who address one another as "brother" and "sister." The letter implicates at least three of the series villains as members... and could possibly implicate all of them as members. Oh, Crap! Fanon, especially the Fan Sequel and Fan Remake games will cheerfully run with this theory.
• Most Kirby games, while sometimes direct sequels to one another, are usually episodic. Around Kirby's Return to Dream Land, however, past games began to tie in more explicitly to newer ones, with Magolor mentioning how the ancients who built the Lor Starcutter made "clockwork stars" (implying a connection to Kirby Super Star's NOVA), the Dimension Mirror from Kirby & the Amazing Mirror being the cause of Queen Sectonia's tyrannical personality in Kirby: Triple Deluxe, Kirby: Planet Robobot's Final Boss bearing a strong resemblance to NOVA, even having wish-granting powers and a similar Heart Drive that's fought as a boss, and Kirby Star Allies making implied connections between the game's antagonists and Dark Matter from the so-called "Dark Matter Trilogy", due to Hyness' Motive Rant and Void Termina's final form.
  • The "Magolor Epilogue" from Kirby's Return To Dream Land Deluxe serves as a Stealth Prequel to Team Kirby Clash Deluxe and Super Kirby Clash, revealing how Magolor obtained the very first Gem Apple and ultimately wound up in Dream Kingdom.
• Mega Man:
  • "Evolution requires sacrifice." Spoken by Lumine of Mega Man X8 and Serpent of Mega Man ZX, this refers to the evolution of the Reploids into something else... Granted, those two are in a future (and a world) that anything's possible with the Reploids (or technology in general). And then, in the Video Game Remake (and possibly Continuity Reboot) Mega Man: Maverick Hunter X, Sigma begins spreading these beliefs himself. If the reboot series wasn't axed, the developers could have elaborated on the concept even more.
  • Meanwhile, in Mega Man Zero, unlike the two series that preceded it, there is a different Big Bad for the first two games (Copy X and Elpizo, who are trying to wipe out Reploidkind and humans, respectively). Then, that novelty just had to be shot down by Zero 3, wherein that game's Big Bad, Dr. Weil, can be easily marked responsible for the events of the previous two ^note he's the one who brought the world to its apocalyptic state and was also responsible for The Corruption of the Mother Elf into the Dark Elf, which was the key to Elpizo's goals in Z2 as well as the reason for Neo Arcadia's The Good King X going missing (thus leading to the creation of Copy X as a replacement), legibly making him the Greater-Scope Villain for the entire Zero series.
  • Wily claims to have orchestrated Mega Man Battle Network 2 at the end of Battle Network 3, making the first three games in the series one saga about Wily's plots to destroy the Internet (really) culminating with the Alpha plan in 3.
• Metal Gear:
  • Metal Gear Solid was mostly self-contained, despite being a sequel to the MSX games Metal Gear and Metal Gear 2: Solid Snake. Metal Gear Solid 2: Sons of Liberty introduced The Patriots, whose operatives were largely responsible for the events in the series. Metal Gear Solid 3: Snake Eater's place in the Patriots arc is their origin story (as evident by the password Zero instructs Snake to use when he meets ADAM), but it's missed by many until Metal Gear Solid 4: Guns of the Patriots spells it out because the Patriots as they exist by the time Sons of Liberty takes place are very, very different than the organization used to be.
  • Further welding is suggested in the Metal Gear Solid 4 novelisation, which adds in things like the technique Ocelot used to become Liquid in 4 was the same technique used in the attempt to turn Raiden into Snake in 2.
• When it was originally released, the whole Metroid Prime Trilogy (despite the Prime name becoming the primary moniker for mainline 3D Metroid games) was designed to be a series of Gaiden Games story-wise, not having any major effect on the series' primary Myth Arc involving the war against the Space Pirates, mostly just showing the status quo being maintained during the Phazon Crisis. The games did not have the "direct" involvement of series co-creator Yoshio Sakamoto, but interviews have noted he had to approve the storylines of the Prime games in order to make sure they didn't contradict the main storyline and is quoted as saying making them completely non-canon would have been "a cop-out." Indeed, Japanese manual for Zero Mission did show the placement of the early Prime games in a timeline on the table of contents. Despite this, the Prime games could be completely ignored in the grand scheme of the series and didn’t have any major ties to the main lore, serving as something more akin to an expanded universe for a long time. Even Other M, which had Sakamoto's more direct involvement, mostly ignored and glossed over the events of the Prime series outside of some very light acknowledgement in the form of the Seeker Missiles and some more substantial, but lost in localization acknowledgement via Project "Metroid Warriors", which shares the same Japanese name as a Pirate Log from Prime 1 involving the space pirates attempting to eliminate the Metroids' weakness to cold and alludes very briefly to the Pirates' own efforts, in spite of Sakamoto's insistence in interviews that they "took cues" from the Prime games. This caused some minor Continuity Snarl with Ridley, as he went from being a near completely cybernetic being to being completely organic again at the start of Super Metroid without any apparent explanation, even if we accept Word of God at the time of the Prime trilogy's release that Ridley survived both the first Prime and Corruption intact without being too much worse for wear in either case. It wasn't until Samus Returns, a remake of Return of Samus, when the Prime series was finally connected in a substantial manner with the "primary" arc, where newly added Final Boss Ridley appears with his cybernetic body parts after his time in the Prime trilogy, showing he's almost completely healed at the time of Samus Returns, and a post credits scene showing him having completely discarded the armor and chasing Samus to the Ceres Space Colony, now fully organic and closing the plot hole. The fight even foreshadows Ridley’s confrontations in both Super and Other M while it's at it, effectively bringing the entire series thus far together into a singular cohesive narrative. Not to bring up all the other aspects of the greater Prime trilogy lore that was brought back up in the game, at least the lore that involved the Chozo.
• Pokémon Mystery Dungeon: Explorers had few story arcs in the first place, but near the end of the game, you find out that Darkrai was responsible for both Primal Dialga and Palkia trying to remove you from time and space respectively.
• Sonic the Hedgehog:
  • For almost 20 years, Sonic CD was a Gaiden Game with no set place in the series' timeline. (Due to the lack of Tails or Super Sonic and the fact it was meant to be Sonic 2, most fans just assumed it was a prequel.) However, as of the new remake for Xbox Live, PlayStation Network, and iPhones, features were added suggesting (and Word of God asserted) that it actually occurred sometime before Sonic 4, and it's specifically tied to Episode II.
  • Sonic Origins would later place CD after Sonic 1, with a newly animated cutscene at the end showing Sonic flying the Tornado away from Never Lake while Amy flips over tarot cards symbolizing Tails and Knuckles bridging the two together.
  • Sonic Frontiers takes everything fans knew about the most of the lore and flip it on it's head, with the story providing the origins for the Chaos Emeralds as well as the Chao and Chaos.
• Star Trek Online has a number of Arc Welding as it takes everything it can from the TV series, movies, and other sources. Among those:
  • Miral Paris' role as the Klingon Messiah is tied into how the Klingons regain their ridged foreheads between the original series and Star Trek: The Motion Picture.
  • Near the end of Star Trek: Deep Space Nine, a group of Dominion ships is threatening to invade the titular DS9 by way of the Bajorian wormhole when suddenly they just disappear! They return in the Featured Episode series "The 2800".
  • Probably the biggest one? The game's true Big Bad? The Iconians, a group of not-so-extinct race that had ruled the galaxy thousands of years ago whose technology had been a real thorn in Picard and Sisko's sides when they encountered them in Star Trek: The Next Generation and Star Trek: Deep Space Nine. Even worse, it's them who had helped caused the destruction of Romulus and Remus in the backstory to Star Trek (2009)!
  • The Foundry, in turn, has been known to pull this on the canon game, especially with the very episodic and frequently disconnected Federation missions. A prime example is the mission "Divide ut Regnes", which in the process of fixing the much-maligned "Divide et Impera" finds time to retroactively explain two aspects of the mission "Preemptive Strike": why the Romulans are preparing to attack the Federation^*They're retaliating for your time-traveling starship hitting one of their facilities to capture an Undine infiltrator and killing everybody (or so they think; it was the Undine who actually did the killing but they have no way of knowing)., and how Admiral T'nae knew about it^*Your time-traveling future self told her..
• Super Robot Wars is a Massive Multiplayer Crossover series of Humongous Mecha shows. Many games often do this by drawing on similarities between different series to weave common bonds.
  • The biggest example occurred in the first Super Robot Wars Alpha game. The Big Bad has an extremely long sequence where he explains how he was behind everything in every series that was in crossed over in the game. This created a meme in the Japanese fanbase where the villain claims responsibility for just about everything. Then in the second Super Robot Wars: Original Generation game, the Big Bad of Alpha reappeared and made another long speech about how he was behind everything. It's fully Ascended Meme.
  • Super Robot Wars UX:
    • By the way, the island covered by the gravity curtain was apparently a research center for gravity engine cores since World War II (a key plot point to The Wings of Rean).
    • Linebarrel is connected to Demonbane because the latter is also a "Machina" and the Katou Organization are hunting them down. More specifically, Linebarrel and Demonbane are known as "Deus Ex Machina". Both stories' time loop events are interconnected in UX.
    • Tatsumiya Island is a part of the Orb Union.
    • Considering the whole Machina idea or rather the meaning behind it is machine god. Linebarrel's Juda seems central to the whole idea of gathering Demonbane, SD Gundam, Machina, Fei-Yen HD and even partially Heroman as a collection of possible Machinas, though obviously not all of them have the idea of a Machina god behind them or rather behind their respective series like Linebarrel and Demonbane do. This would be a reason for Juda and a way to tie in a lot of the story together.
    • Scenario 24 is a mash of the starting battle from Sayonara no Tsubassa as well as the titular impact of Trailblazer, by mixing in the fact that the Galaxy refugee ships were at Jupiter. Fighting Vajra ships for the first time is only a tease to the real first appearance of the ELS. This also gives the chance for more interactions between Alto and Setsuna, and the final save coming from Tieria in the Raphael.
    • Fei-Yen's plot is tied in with Mazinkaiser SKL, where it is the robot used by the female kingdom. She starts out really reserved, then once you go on SKL/Macross route split she has an encounter with Miku^*Note that in game she never mention Miku's name and gets her KYUNKYUN beam, then during SKL finale she goes super mode^*which is basically Fei-Yen's original Super Mode when Kiba shows up, and during Fafner TV finale, she gets her Morale boosting special command. In the Blue Sky and Operation Azure. Sink it for a moment.
    • The Tokyo in the interior of the moon, which is from where all the Humanoid Machinas stem from, is also strikingly similar to Shou's Tokyo. Shou and the Dunbine characters are basically from a previous incarnation of the world. Later on we find out Juda's "view of future" is actually about what happened before, so at least part of the cast are also of the same origin.
  • Super Robot Wars V:
    • Mazinger Edition Z: The Impact! never got a second season, and consequently never went into the Great Mazinger storyline despite some foreshadowing. As such, Shin Mazinger Zero vs The Great General of Darkness is brought in to give Great some proper representation.
    • The timeline of Space Battleship Yamato 2199 and late UC is referred to as the NCC, or New Correct Century, as if it were a singular Gundam timeline, 100 years after the events of Char's Counterattack.
    • Draconium is derived from the Getter Rays and since the Dragons are humans who evolved into Dragons to purify the land from the radiation, they can temporarily make the Shin Getter weaker.
    • Aeolia is also another member of the Ancient People who seeks to overthrow Embryo.
    • Ruri is another successful Ultimate Coordinator.
    • Black Noir manipulated Embryo, the events involving the male protagonists from the AD Dimension, and a couple other things just to enjoy as a game. When Aeolia learned of Black Noir, the former created Veda as a countermeasure.
    • Much of the plot of Getter Robo Armageddon is folded into the plot of Shin Mazinger, such as Great Mazinger and Mazin Emperor G being powered by both getter rays and photonic energy and Kenzo Kabuto constructing the Shin Getter Dragon.
    • Banjo Haran was raised on Mars, meaning he's an A-Class Jumper and thus capable of Boson Jumping.
  • Super Robot Wars X
    • "Soukaizan," "The Country of Beasts (Kamina City included)," and "The Country of Mana" makes the world of Al-Warth.
    • Wataru’s own world of Japan is the same as The Brave Express Might Gaine, and the Shin Mazinger series. With Wataru living in Nouvelle Tokyo City, and himself being friends with Tetsuya Yoshinaga.
    • Shou Zama is an Area 11 citizen, while Todd Guiness and Marvel Frozen are Brittanians. Also, Gundam Wing, Dunbine, and Code Geass are part of the same world.
• The individual biomes in the submarine exploration game We Need to go Deeper appear to have nothing to do with each other, however there is an overarching story behind the Living Infinite and some connections between the areas.
  • The Lair Guardians scattered throughout the levels were placed there by the crew of the Nautilus to stop people from diving deeper, and are made of special metals taken from the Meteor. The glowing green energy that powers them is the same as those of the eldritch shrines, as well as the eldritch staff weapon.
  • The Time Traveler seems like a goofy character added to mix up the gameplay a bit, but he's aware of the Ancient One and became an ally of Captain Nemo as the two worked together to prevent its awakening.
  • A few messages imply that the Life Gems which empower the undead creatures in the Cursed Waters originated in the Aurelian Depths.
  • The volcanic turtle enemies shoot the same spike balls as the flowers in the Ancient Abyss, implying the turtles collect them from deeper waters to attack with.
  • Denizens of a few civilizations imply that the biome's boss is actually holding back worse creatures from lower biomes, or preventing anyone from diving deeper and waking the Ancient One.
• Late in Xenoblade Chronicles 2, it's revealed that Zanza, the Big Bad from the first game, was actually the evil Literal Split Personality of the Architect/Klaus, the Big Good of 2. The third Aegis, Ontos, is also all-but-stated to be another character from the first game, Alvis. Furthermore, the stories of both games are taking place simultaneously, with the Architect aware that he'll die once Shulk's party kills Zanza.
• Near the end of Xenoblade Chronicles 3: Future Redeemed, the heroes are shown a memory of the original Earth, with a radio broadcast in the background mentioning the Earthlife Colonization Project from Xenoblade Chronicles X, Dimitri Yuriev from Xenosaga, and Philadelphia-class Motherships from Xenogears, implying that those games exist in the same universe as the main Xenoblade Chronicles games and formally bridging all of Tetsuya Takahashi's works together.

Visual Novels

• Ace Attorney Investigations: Miles Edgeworth:
  • In both games, the first four seemingly unrelated cases turn out to have all been part of the Big Bad's Batman Gambit. In fact, the main point of the final case is for the player to figure it out. It is, however, subtly foreshadowed from the beginning, and the hints are there if you look for them.
  • In the second game, the Berry Big Circus (focal point of the most base-breaking case in the series, "Turnabout Big Top") winds up being the place of employment and unwitting facilitator of several plans of that game's Big Bad. Considering most of the references to non-Investigations games being little more than The Cameo, this one stands out. Meanwhile, 2 also ties in the main arc of the first game to an even greater scale, due to the Inherited Turnabout prominently featuring playable segments as the Gregory Edgeworth during his ultimately-fatal last case. Due to tying it in with the Investigations games' Myth Arc, the events behind his final case against Manfred von Karma are given even more significance in the grand scheme of things.
• In Fallen London, the player themselves can engage in a tiny bit of this at one point in the "Seeking Mr. Eaten's Name" Story, where the player character is asked why they persist in their quest despite their assured destruction. You can choose from over a dozen (!) possible responses, and some of them reference Stories that occurred earlier in the game. For example, you can imply that your character has never been the same since, say, their visit to the Iron Republic or being exiled from the Shuttered Palace.
• Despite Nine Hours, Nine Persons, Nine Doors feeling like a self-contained story, its sequel Virtue's Last Reward manages to very successfully connect it to that game's Myth Arc (and by extension the overall plot of the eventual trilogy) by revealing that Gentarou Hongou, aka Ace, was a member of Free the Soul, and that Cradle Pharmaceutical and his experiments with the morphogenetic field were funded by the cult. The symbol on the robes Snake was forced to wear in 999 is also used as Free the Soul's coat of arms.

Web Comics

• Dominic Deegan: It turns out the King of Callan, who wants humanity/himself to control the source of magic (which is apparently a comet) so badly he tried to destroy an entire country and wipe out its people when it was their "turn" use it was responsible for just about every catastrophe in the comic.
• It's Walky!/Roomies/Joyce and Walky. The entire storyline consists of retconning arcs to weld them into bigger arcs reaching further into the past, culminating in a gigantic "conclusion" arc connecting every character that ever appeared in the comic into a huge overarching plot (whose final resolution ends the comic).

Web Original

• SCP-2000 double-checks the welding around the SCP Foundation. Officially it's all been linked for several real-life years, but in practice it's a massively disparate collection of collaborative stories on a wiki with an extremely loose version of "canon".

Western Animation

• Various jokes and gags made in the purely episodic first season of Adventure Time either return in later seasons to add to the show's overall Myth Arc, or are re-contextualized to bring more insight into a character. One of the most notable examples of this is the season four episode "I Remember You", which takes an early throwaway gag of Marceline constantly moving all over the Land of Ooo, and explains that the main reason for this is to avoid her now mentally-insane father figure, the Ice King, who took care of her during the nuclear apocalypse but can no longer remember the bond they once shared.
• Parodied in Clone High's final episode, where the Shadowy Board of Directors bring together literally every one-shot guest character or celebrity and address them as collaborators. Of course, this was mostly just so the episode could end with literally every character ever to appear on the show — except Scudworth — frozen inside a meat locker.
• The Futurama episode "The Why of Fry" reveals that Fry coming to the future was part of a wider conspiracy, as his lack of delta brain wave made him the only person who could save the Universe from the Brainspawn. Whilst at least part of this was planned from the beginning of the show, the events of "Roswell That Ends Well" (where Fry becomes his own grandfather) were used as an explanation for the lack of brain wave, which was not part of the original plan.
• Gargoyles:
  • Most of the middle part of season 2 was already an arc, but then, during the two-part episode "The Gathering", where you see Oberon's Children filing into his castle to be recognized by him back on Avalon—and you realize they're familiar to you. Odin, Anansi, Banshee, Coyote, even Anubis are all his subjects. How powerful, then, must Oberon be? This was already a Story Arc of sorts—though Angela's, Goliath's, and Elisa's adventures were episodic, they were already linked by their method of travel—but now you see it was all part of a second arc as well, to set up the Story Arc finale.
  • Also, many unrelated aspects of the first half of the series were ultimately revealed as part of the Archmage's far-reaching Batman Gambit for world domination.
• Used not in Gravity Falls, but in the show's credits. At the end of each episode, there's a coded message in the credits. Despite their secretive nature, however, the messages are very simple and mostly just are cheap jokes. After Season 1 ends though, Dipper's Guide to the Unexplained comes out, and each short ends with a piece of a secret message that has to be decoded by looking through the season's credits messages. This message was obviously formed after the fact, but allowed for the credits' messages to have actual significance among speculating fans.
  • Word of God confirms that the first season's Monster of the Week approach to episodes were mostly because of Disney not knowing if a mystery show would sit well with audiences. After gaining significant popularity, the show was arc-welded with a conclusive first season ending, that led to a more cohesive Story Arc in season 2.
• The Legend of Korra: "The Stakeout" reveals that Unalaq, the Big Bad of Book 2, was a member of the Red Lotus, the villains of Book 3, and he aided their attempt to kidnap Korra. However, he later turned on them, and his plan to become a Dark Avatar was not the Red Lotus's plan.
• My Little Pony: Friendship Is Magic:
  • Throughout Season 4, each of the Mane Six gets a focus episode during which they receive a gift, which at the end is shown giving off a rainbow glow. In the season finale, these are revealed to have become the keys to open the mysterious box which emerged from the Tree of Harmony in the season premiere.
  • Several episodes throughout Season 7 feature stories about various legendary heroes from Equestria's past. The season finale reveals that all of them, along with Starswirl the Bearded (another legendary figure, mentioned repeatedly since Season 2), were part of the same group, the Pillars of Harmony.
• Season 3 of OK K.O.! Let's Be Heroes does this for some plot elements from the previous two seasons:
  • Foxtail, the Anti-Villain Big Bad of Season 2's P.O.I.N.T. arc, is revealed to have gotten the glorbs she used to illegally power up P.O.I.N.T. Prep students from Shadowy Figure, K.O.'s Arch-Enemy and the series's final Big Bad, who's shown an interest in almost every one of his appearances in obtaining these glorbs to sell on the black market.
  • Three characters who had previously never so much as appeared in the same episode together turn out to have a very important connection : 1) Laserblast, a Posthumous Character who's important to the P.O.I.N.T. backstory and storyline because, among other things, his death was the aforementioned Foxtail's Cynicism Catalyst that led to her becoming a Well-Intentioned Extremist. Oh, also he's alive and K.O.'s father; 2) Professor Venomous, Boxman's business partner who has begun to take a more active role in attacking the Plaza and antagonizing the heroes, and 3) Shadowy Figure, the aforementioned Arch-Enemy of K.O. who tries to steal glorbs and get K.O. to give in to his anger and unleash his Superpowered Evil Side. This connection is that all three of them are the same person. Laserblast made a Face–Heel Turn and became a villain, adopting "Professor Venomous" as his new alias; Shadowy Figure, meanwhile, is his Split Personality Turbo form.
• The South Park episodes "200" and "201" begin as a follow-up to "Trapped in the Closet" and then tie together the plots in "Mecha-Streisand," "Ginger Kids," "Scott Tenorman Must Die," "The Super Best Friends," "Butt Out," "Fat Butt and Pancake Head," the "Cartoon Wars" two-parter, and "Cartman's Mom Is Still a Dirty Slut," and this does not include the numerous previously one-shot characters who make another appearance in this two-parter.
  • Season 23 has an episode where Randy goes to China. Not long after the season ended, COVID-19 became a thing, and, as you would expect, got written into the show. Guess who Patient Zero turned out to be.
• During Rudolph and Frosty's Christmas in July, it is revealed that the "foggy Christmas Eve" from the earlier Rudolph the Red-Nosed Reindeer (1964) was caused by the wizard Winterbolt, and Rudolph's nose was gift from Lady Boreal to stop him.
• The Stroker and Hoop finale has them kidnapped along with Double Wide and put inside K.A.R.R over a canyon while being taunted by their kidnapper who gives them three guesses on who he is lest he drops them in the canyon. Through the whole episode the three call back recent episodes and go over suspects. Its eventually revealed to be a no name background character whose appearance changed in each encounter with the duo save for his voice.
• Transformers: Animated had Ratchet's war flashbacks; in "Thrill of the Hunt" he flashes back to serving alongside Arcee, and in "A Bridge Too Close" he recalls having served in the war with Omega Supreme, also the Autobots' ship, as an old friend. The third season reveals that Arcee's role as intelligence officer during the war had actually been to carry the activation codes necessary to utilize Omega Supreme, an experimental weapon.
• W.I.T.C.H. (2004): The second season explicitly does this via Nerissa, particularly when she reveals that she was posing as multiple characters in season 1 to help La Résistance, and had a child under one of these false identities specifically in order to give the rebels a Rebel Leader who could bring them to victory.

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