Myth Arc

Like a Story Arc, but longer -- spanning the entire series.

The term originated with The X-Files (whose writers referred to its alien conspiracy episodes as "mythology episodes," a term which itself has fallen into common usage), though Babylon 5 is probably a better example of an effective Myth Arc. Comparing The X-Files to Babylon 5 provides an object lesson in the value of knowing where you're headed when you set up a large-scale arc: both series had slow-building (often season-spanning) stories, but Babylon 5 would eventually resolve its stories while The X-Files overarching plot just got strung along further and further, until -- in what's now called The Chris Carter Effect -- its viewers lost confidence that the plots would ever be resolved.

In some shows -- such as the aforementioned series -- the trend is to alternate between Myth Arc stories and Monster of the Week episodes, making it easier for new viewers to get into the show and ensuring some short-term gratification while keeping the viewer's interest over the long run. However, heavily arc-based shows like Heroes show that the American public is willing to invest their time over longer periods too.

Anime series very often have arcs running the entirety of their series, which can span hundreds of episodes, with examples such as Macross, Neon Genesis Evangelion, Martian Successor Nadesico, various Gundam shows, Noir (which had a Myth Arc from the very first episode), and others. The predominance of such arc-based plotting in anime (many of which were introduced to foreign audiences in the mid 90s), as opposed to the generally episodic nature of American TV series of the 80s and 90s, is part of what led to the massive rise in anime's popularity with the nerd-core at that time, and many suspect that the development of multiple Myth Arc-based shows on American television in the 2000s was a reaction to that.

Can lead to a Continuity Lock Out.

Anime and Manga

 * Legend of the Galactic Heroes has one of these.
 * Neon Genesis Evangelion has the war on the Angels, which is later revealed to be a small part of
 * However, the Series never actually explain the real circumstances behind the War with the Angels in the context of the Show itself, leading to the inevitable mindscrew it's infamous for.
 * The Macross franchise, in addition to having individual arcs in its shows, possesses several myth arcs that run throughout the franchise, including learning more about the Protoculture and the origins of mankind and the Zentraedi, and finding worlds to replace the seriously damaged Earth.
 * While generally considered a horrible Macekre, the Robotech franchise born from Macross possesses a somewhat similar but altered Myth Arc involving the Masters and their manipulation of multiple races throughout the galaxy, which culminates in the Earth becoming a shooting gallery for several interstellar conflicts fighting over protoculture. Except in Robotech it's a sort of living energy useful for hyperspace travel, while in Macross it's an actual culture from Precursors.
 * Tengen Toppa Gurren Lagann starts off as an episodic action/adventure/mecha series following a small band of rebels fighting the Beastmen, who had driven humanity underground. After a mindblowing plot twist followed by some significant Character Development, the series developed into a full-blown war-story. However, after a Time Skip, it is revealed that the war was nothing more than a tiny part of the whole picture.
 * The modern remake of Bubblegum Crisis, subtitled Tokyo: 2040 significantly differed from its predecessor in having a significantly developed myth arc, as opposed to the prior's tendency to single episodes and two-parters at most.
 * Naruto started off with a single largely free-standing arc; the second arc kicked off a Myth Arc that has dominated the storyline (at least in the manga) ever since.
 * The main myth arc of One Piece is Luffy's quest to become the Pirate King, which starts in the first chapter. Another one starting later in the series revolves around the conflicts between the main powers of the world, how the main characters' actions affect the balance, and the secret history of the world.
 * Dragon Ball had quite a few. The first were Goku's tail and unexplained powers and the Dragon Balls themselves, which were both introduced in the very first arc, but weren't resolved until Dragon Ball Z. There was another relating to the shared history of Piccolo and Kami, one involving Son Goku's gradual ascension into the mythical Super Saiyan, and one involving Son Gohan's hidden powers.
 * Ash's goal To Be a Master in the Pokémon anime. In each and every saga.
 * Case Closed, the protagonist is turned into a child by poison and seeks to those responsible.
 * Cowboy Bebop, while mostly episodic, has two basic plots running through the whole series:.
 * And from the same creator, Samurai Champloo has the search for the Sunflower Samurai.
 * One could argue that this was the case for anything involving Sosuke Aizen from Bleach. A few more arguable cases from the same series would be the Black and Gray Morality of the Soul Society, the chess-duels between the various Big Goods and Big Bads, the conflicts against the Hollows (and their Arrancar "superiors"}, and The Hero's constantly-fluctuating development as a Shinigami.
 * Suzumiya Haruhi alternates between enthralling plots and (usually) comedic side stories. (The novels are either a full story divided into chapters, or full off short stories)
 * Shaman King does this when, sometime between the end of Season 1 and the start of Season 3, the focus of the series leaves the Shaman Fight entirely and delves off into exploring Hao's involvement in, as well as Hao being  . In fact, the series ends before the Shaman King is even decided.
 * It didn't exactly end, it just went on an extremely long and sudden hiatus. The final issues have just been recently published.
 * Yu-Gi-Oh! had the history of the Pharaoh, Millennium Items, and the Shadow Games that advanced with each Story Arc until it's conclusion at the end of the series.
 * Code Geass contains an on-and-off form of Myth Arc revolving around the true nature of the Geass power. This arc begins arguably in the first episode, when Lelouch receives Geass, but the implications of the power are almost always overshadowed by the Britannian/Eleven conflict. The Geass Arc comes into its own later when The Geass Arc effectively ends in Episode 21 of R2, when
 * The whole plot of Death Note is all one Myth Arc: Light, or Kira, attempting to kill L  and L attempting to arrest Kira. Plans wrote this manga.
 * Berserk Is about a highly explosive Love Triangle between three exeptionally powerfull and charismatic but very flawed humans that is used by  to bring humanity under it's absolute control and start an age of pure horror. The whole world is deeply afected, but in the end it all revolves around these three characters and what they mean for each other.
 * Slayers is pretty good at alternating between Myth Arc and filler episodes. While each season will have one story arc spanning it, the three story arcs are intricately connected and form one very long plot.
 * Mahou Sensei Negima has Negi's search for his Disappeared Dad. It doesn't really become central until around volume 6, which is naturally where the anime adaption cut off.
 * Vinland Saga has Thorfinn's dreams of Vinland and the phrase "somewhere not here".
 * Despite the first chapters of Fullmetal Alchemist looking like your usual shonen Adventure Towns, the whole manga is one long and steady Myth Arc, going out of its way to explain how  The author has actually said the ending for the story was the first thing she came up with, and then worked backwards from there.
 * The first anime based on the manga has a different myth arc of its own:
 * All of the recurring story lines in Detective Conan fall under this.
 * Monster: the goal to capture Johann Liebert, naturally.
 * Pretty much the entire first season of Eureka Seven is just foreshadowing for the second half of the series and getting to know the characters.
 * Noir, as mentioned above, had a Myth Arc from the very first episode, which covered Mireille and Kirika's investigation of the Ancient Conspiracy of the "Soldats". At first, the series devoted much of its time to Target Of The Week episodes, but the Myth Arc gradually intensified, eventually completely eclipsing the assassins plot.
 * Madlax similarly had a Nebulous Criminal Conspiracy Myth Arc with The Syndicate of Enfant at its center. The investigation of Enfant completely eclipsed the Mission Of The Week and Slice of Life routine by episode 10, but it wasn't until episode 18 that all Plot Threads converged into the main plot.
 * El Cazador de la Bruja had a Myth Arc regarding the Government Conspiracy called Project Leviathan, of which Ellis was a test subject. It isn't until the final 4-5 episodes that the series abandons its episodic nature to start resolving the Myth Arc.
 * Every season of Digimon has a myth arc, but especially Digimon Tamers which had the season begin with Calumon's arrival into the human world and deeper into the season we find he's  -- not that constant clues weren't given throughout the season.
 * Fairy Tail has the dragons' disappearance (and the number 7) which it will occasionally throw a tidbit out for. So far they've reaffirmed the date they all vanished, hinted that dragon slayers shouldn't actually exist, and most recently had someone spot a dragon, but the heroes are too busy getting into all kinds of weird crap to follow up on this.
 * Saiyuki is a Myth Arc inside a Myth Arc. For the entire first series, the only visible arc is the four heroes' quest to reach India, crush the baddies' nefarious scheme, and restore peace and harmony to Tougenkyo. It's not until midway thru the second series that the real Arc--which finally takes main stage in the third series--begins to reveal itself (why are these particular four on the mission? who is the only human in Houtou Castle? and )
 * Inuyasha was about completing the Shikon jewel and killing Naraku.

Comics

 * One Hundred Bullets, one that only becomes apparent later on via Jigsaw Puzzle Plot.
 * Preacher (Comic Book): Jesse, Tulip, and Cassidy's ongoing search for God.
 * The Sandman is a clever example of a Myth Arc in disguise. While the occasional volume may have some development on what would seem to be an ongoing story (Season Of Mists and Brief Lives) it is not until The Kindly Ones when we learn that nearly all aspects of the series were parts of
 * Lucifer has a more typical one, as events from previous arcs weave into those of the next.
 * Bone, often classified as a more comedic Lord of the Rings.
 * Hellboy is known for this.
 * Transmetropolitan was once described as a "3000 page graphic novel".
 * The Grendel comics are basically one big Myth Arc detailing the beginnings of a young man who becomes an assassin and eventually telling how, in his basic idea and concept, Grendel conquers the planet.
 * IDW's recent Transformers comics seem to be setting up a double Myth Arc. One concerning the Lost Light and it's crew's search for the Knights of Cybertron and another one concerning Bumblebee and the other Autobots attempts to maintain peace on Cybertron (it's not going well to say the least). They also appear to be building up to the return of Optimus Prime.

Literature

 * The Dark Tower is, of course, about Roland's journey to The Dark Tower.
 * Animorphs has one with the Yeerks, namely the overarching conflict across the galaxy. It was basically guaranteed that any book narrated by Ax would discuss this slight bit, any book narrated by Marco would have the myth-arc regarding, and stuff narrated by Tobias would deal with the Hork-Bajir, and the Anti-Morphing Ray arc. The whole series had the myth-arc of the war between Crayak and Ellimist, generally covered in Rachel's narrations.
 * Harry Potter. Every book is about Harry's struggle against Voldemort, in one form or another. The second book seemed like an oddball, Monster of the Week episode, until book six revealed just how well it fit into the overall story.
 * Umberto Eco's novels (The Name of the Rose, Foucault's Pendulum, The Island Of The Day Before, Baudolino, and The Mysterious Flame Of Queen Loana) supposedly form a Myth Arc, but rather infuriatingly, he never says what it is, and the connections are too subtle for anybody else to even begin to guess.
 * The Deryni novels and short stories have interrelated plot arcs that span several centuries.
 * Fraught relations between the kingdoms of Gwynedd and Torenth. A younger son of the Torenthi king invades and conquers Gwynedd; after much suffering and several generations, the old ruling family is restored, but at a high price. Descendants of the Torenthi invaders repeatedly attempt to reclaim Gwynedd over the following centuries, and the claim is ultimately folded back into the Torenthi ruling House of Furstan.
 * Deryni-human relations change dramatically in response to the conquest and restoration. Deryni were open and respected, with established schools teaching the ars magica and Healing in particular. A reactionary segment of human lords spiritual and temporal proclaim Deryni to be anathema to solidify their own power after the restoration. The masses are easily brought to help with the persecution of Deryni, thanks to their lack of sophistication and the efforts of dogmatic churchmen. It literally takes centuries for the right people to come on the scene to openly contest the notion that all Deryni are evil and live to tell the tale--and even then, it's a close-run thing for some of them.
 * Steven Erikson's Malazan Book of the Fallen myth arc covers several hundred thousand years (mostly in backstory) including . The histories of  empires are also mysteries that carry the plot. Dang archeologists.
 * The Lord of the Rings (although it was originally meant to be one book), as well as many other popular fantasy series.
 * The Dresden Files seems to have developed this as of Proven Guilty with the reveal of . Possibly an example of Arc Welding, depending on how much was planned out beforehand.
 * Considering the Council is referred to in all but name at the end of the second book it probably isn't Arc Welding.
 * All of the books in Dennis L. McKiernan's Mithgar series fit this trope. They might seem unrelated at first (many books are stand-alone and can be read without reading the others) however they all play a part in the culmination of the Myth Arc and the defeating of the Big Bad. It's especially impressive considering the books were not written in (in-universe) chronological order.
 * The various Doctor Who Expanded Universe novel series have had their own myth arcs. The Virgin Publishing New Adventures (mostly featuring the 7th Doctor) had a myth arc concerning ; the BBC novels (mostly featuring the 8th Doctor) had a myth arc concerning.
 * Robin Hobb's Realm of the Elderlings 'verse is split into, at present, four different series which in many ways are self-contained. Together, however, they make up one big Myth Arc about the return of the dragons and the White Prophet's quest.
 * The Foundation trilogy is about the psychohistorically predicted decline and fall of the Galactic Empire and the eventual rise of the Foundation to become the next empire.
 * A Song of Ice and Fire - the whole series is essentially covered by a story arc dealing with the troubles revolving the Kingdom's throne and who is to be the supreme ruler, and there's still no end in sight.

Music

 * Ayreon did this, though not chronologically, with the story of Humanity from Planet Y to 2084.
 * Frank Zappa did this with his music; he had a massive stockpile of cultural references, injokes, and musical riffs which he repeatedly drew from over his thirty-year career.
 * Coheed and Cambria's music is one enormous myth arc.
 * Complete with a tie-in comic book. Written by Claudio Sanchez himself!
 * Craig Finn's bands, Lifter Puller and The Hold Steady both contain myth-arcs of a sort.
 * Brave Saint Saturn's three albums all told a single story about a manned mission to Saturn that went awry.
 * Rhapsody of Fire tells the tale of the defeat of Nekron through most of their albums.

Television

 * Lost has a Myth Arc built in, though it is a bone of contention as to whether the authors actually knew where they were headed or not (see Twin Peaks).
 * The official line from the creators is that they knew how they wanted to end the series, and how to direct the plotlines to get there. Now that it is over, debate rages as to whether the last season was a fulfillment of a proper Myth Arc or an Ass Pull.
 * Unsurprisingly, a number of shows that tried to cash in on the success of Lost had them, too: Invasion, Threshold, Surface -- well, we assume they did; they were cancelled before the arcs could develop.
 * More successful were The 4400 and Heroes, although the former actually predated Lost by a good few months.
 * In Castle finding who killed Beckett's mother, and the organization behind him
 * Twin Peaks looked like it had a Myth Arc, but David Lynch later admitted he had been making it all up as he went along.
 * Both versions of Battlestar Galactica were arc-based, though elements thereof were made up on the fly; in the 2000s version, for example, the one-shot character Sam Anders was reintroduced into the arc 15 episodes after his first appearance, and became a recurring character in Season 3, because actress Katee Sackhoff (Starbuck) wanted her character to have a love interest. By season 4 it is fair to say that he has suddenly become absolutely vital to the ongoing (and soon to be ending) arc.
 * Before Sam Anders, another one-shot character who ended up being relatively fundamental to an ongoing plot point of Galactica is Karl "Helo" Agathon. Originally he was supposed to die abandoned in Caprica during the miniseries. The Powers that Be liked him enough to bring him back to eventually be and occasionally the second in command of Galactica herself.
 * While Supernatural is also a Monster of the Week show, the main ongoing plot-driven arc is tied directly into the long-term plans that a demon had for the Winchester family, and specifically, Sam and Dean's attempts to figure out what those plans are and to thwart them. (With various degrees of success. All four of the Winchesters have had significant Nice Job Breaking It, Hero moments.) The first couple of seasons almost implied that Sam alone was key to the Myth Arc, but hints such as the anvils dropped in Faith and Houses Of The Holy or the YED preferring to spend more time breaking down/taunting Dean rather than on Sam in both of their major confrontations suggested throughout that Dean was pretty important himself. Cue Seasons Four and Five and both brothers are held on an approximately equal level in terms of the Myth Arc and neither of them wants the job.
 * The entire run of classic and new series Doctor Who has a few common threads running through; most notably, the premise of "Doctor who?" has varying surges of interest in different series; the new series has picked up on the mystery behind the Doctor's name again, with . Whether or not these questions can be classed as arcs probably hinges upon whether they were ever intended to be answered.
 * With the new series, the production teams of both Russell T Davies and Steven Moffat have taken to building up series-long Myth Arcs. This is done by adding subtle hints, clues, and foreshadowing throughout the episodes until the series finale, where the events are explained and the loose ends are tied up.
 * Series 1 dealt with the words Bad Wolf being scattered through time, as well as the effects of the Time War on The Doctor.
 * Series 2 dealt with the Torchwood Institute. The events of the series ended up feeding into the spin-off series Torchwood.
 * Series 3 dealt with the mysterious Harry Saxon...
 * Series 4 dealt with the mysterious disappearances of various planets.
 * The first four series' of the "nuWho" revival eventually coalesce into a Myth Arc in the Series 4 finale and in The End of Time special, which both draw elements from every preceding series as well as featuring every major recurring character up to that point.
 * Series 5 dealt with cracks in time and space appearing during the Doctor's travels.
 * Series 6 dealt with the relationship between the birth of Melody Pond, the identity of River Song,, and the shadowy organization known only as The Silence.
 * The fifth and sixth seem to be building a Myth Arc of their own, based around the relationship between The Doctor and River Song, The Silence,.
 * Fringe started off as a Monster of the Week show, with some mythology elements seeded in to keep the traditional J.J. Abrams crowd interested. Over time, however, the procedural elements have taken a definite backseat to the story arc. While there are still a fair number of episodes with a case of the week, often towards the middle of the season, the Myth Arc still tends to feature prominently in them.
 * Originally intended to be an episodic supernatural-mystery-of-the-week series, Angel began developing a myth arc of its own with its first season finale, involving Angel and friends being pivotal players in an upcoming apocalypse. Your Mileage May Vary as to how well it was pulled off.
 * The Sarah Connor Chronicles has a running Myth Arc regarding the characters preventing Skynet's creation and Judgment Day, though it also focuses on numerous subplots and a lot of personal character development.
 * Power Rangers is suspected to have a bit of a thin one -- introduce villain's empire in season 4, give villain motive in season 6 by destroying said empire, show long-term aftermath of villain's attack in season 9, introduce villain in season 10, show how planet will become vulnerable in season 13, then show the actual fight against the villain and the attack itself in season 17.
 * Earth: Final Conflict was both loved and praised by its fans for its complicated, multidimensional and just way too convoluted arc. The writers were smart enough to make all things vague and open to personal interpretation to avoid an inevitable Series Continuity Error and mostly let the viewer himself discern right from wrong.
 * Babylon 5, as mentioned in the article itself, is one of the archetypical Myth Arcs, and often credited/blamed for the proliferation of Myth Arcs in science fiction shows since.
 * The quirky Police Procedural Life was an example of the mixture idea: while each episode involved solving an individual Mystery of the Week, most episodes would also involve the main character's quest discover who arranged for him to be wrongfully convicted of murder. This story was left largely hanging by the series' abrupt cancellation. While, by the second season's finale, he had learned why he was framed, he had not learned who (and since the "why" was the second one claimed in as many seasons, that, too, could have been merely a Red Herring).
 * The Mentalist has the mystery of finding out who the serial killer Red John is.
 * Monk: Finding out who murdered Trudy Monk.
 * Following Monk, the various "quirky" shows on USA Network have also adopted the system of having a Myth Arc across episodes that mostly focus on Mystery of the Week or Monster of the Week episodes. As follows, they are:
 * Burn Notice: Who burned Michael Westen? How can he get un-burned? Will he get un-burned at all? And who exactly is going about starting wars for the money?
 * White Collar: Who is the Man with the Ring? What happened/ Kate? And what will become of the music box?
 * Royal Pains: What's wrong with HankMed's mysterious benefactor, Boris? And what exactly was/is Eddie R. Lawson up to?
 * Alias was a otherwise straightforward Tuxedo and Martini spy drama, but also had a show-spanning Myth Arc involving a Leonardo da Vinci knockoff Renaissance inventor named Milo Rambaldi.
 * Star Trek: Deep Space Nine had the conflict with the Dominion; although the Dominion wasn't even mentioned for the first season, the claiming of the wormhole to the Gamma Quadrant in the pilot episode sets up this conflict.
 * Person of Interest has a strong Myth Arc surrounding the Machine, the advanced surveillance supercomputer that identifies each episode's Victim of the Week for the protagonists to help. Most episodes flesh out a different aspect, either how it was created (via Finch's flashbacks), what various superpowers will do to obtain or control it (via Reese's flashbacks and several present-day stories) or just what the Machine has become capable of on its own.
 * As noted at the top of the page, X-Files starts out as a semi-episodic Monster of the Week style mystery show but over time, it develops an overarching storyline concerning a government conspiracy and possible alien activity. Unfortunatly the arc wasen't resolved by the time of the final episode which ends revealing that all this abduction, conspiracy, alien stuff is linked to a possible full-on.

Video Games

 * The Might and Magic games have individual plots that are quite simple and a much more complex plot that spans the entire series as well alternating with the Heroes of Might and Magic spinoff series. Playing the entire franchise in the fiction's chronological order can be very interesting as all the pieces of the puzzle click together.
 * Heroes of Might and Magic V, its addons, and Dark Messiah together form another Myth Arc.
 * There were exceptions: Heroes II's expansion were unconnected to the rest (indeed, not even all the campaigns in the expansion appears to take place in the same world), Might and Magic IX dropped the thread that had bound all RPG Might and Magic games up to then, and Heroes IV's expansions were more-or-less only connected via taking place on the same world as Heroes IV, away from both Heroes IV's and Might and Magic IX's settings and stories.
 * Metal Gear Solid. Good god Metal Gear Solid... though there's a school of thought that Kojima was just making it up and retconning as he went along. Reportedly, he wanted to end the series with Metal Gear Solid, but got pressured into continuing. Taking four whole games on 3 different consoles to setup and resolve the arc might be his way of getting revenge.
 * The "Xehanort Saga" of the Kingdom Hearts series.
 * Fallout is building up a decent Myth Arc and it will be interesting to see what parts of it are carried on into New Vegas -- there are two main strands to this: firstly the story of how the world ended up the way it did, and how the Government with its Crapsaccharine Vault Experiments became the Enclave which is encountered by the PC in 2 and 3, and had its sticky little fingers in the FEV virus you discover in one. Secondly, the story is about how the world is on the road to some kind of recovery -- in every game so far, the world has been slightly more built-up, less sparsely populated and a little less Crapsack World than the last, and the player can affect this progress; hindering by destroying entire settlements or helping by improving the ones that exist. Each game also gives you the chance to help Harold, who is, if you keep him alive in Fallout 3, pretty much the only way the desert will ever become green again. All of this makes gritty little Fallout one of the most idealistic video games out there, in an Earn Your Happy Ending kind of way.
 * Fallout: New Vegas in particular has a Myth Arc in it's DLC involving Ulysses, the original courier who was to deliver the Platinum Chip who has some past history with the Courier. Their final confrontation is the entire point of the DLC Lonesome Road.
 * The Assassin's Creed series appears on the surface to be a Stealth Based Game where you play as a Badass who murders a lot of people with a fancy knife. Fair enough, but the series also contains a Framing Story that is largely omitted from the advertising: these ancient lives are being relived in the present day by a man named Desmond Miles, who is using a device called the Animus to access a VR simulation of his Genetic Memory. This comes about as the culmination of a millennia-long Secret War between the Templars and Assassins over the right to control humanity's future. The war is focused on a series of artifacts left behind by The Ones Who Came Before, an ancient civilization that created humankind before dying in some kind of catastrophe. Further, said civilization foresaw their doom and left behind messages embedded in these artifacts, as well as a special genetic legacy, all in an attempt to Fling a Light Into the Future so that Desmond, in 2012, can stop The End of the World as We Know It from happening again. All of human history is a carefully crafted lie designed to conceal this struggle, as is revealed in cryptic "Truth" puzzles throughout the games.
 * The relatively minor Morrigan/Flemeth plot in Dragon Age and Dragon Age 2, especially after Flemeth's cryptic remarks in the second game and Morrigan's Sequel Hook at the end of Witch Hunt, suggest that the entire saga of seemingly unrelated tales is being set up as a massive Gambit Roulette war between the two.
 * inFAMOUS has the story of the Ray Sphere and the threat of the Beast span both of it's games.
 * The Metroid Prime games follow a story arc centered around the mutagen known as Phazon: The first game introduces Phazon in the dying world of Tallon IV and also showed the downfall of the Chozo civilization and the attempts of the Space Pirates to mine it; the second showed a planet locked in perpetual dimensional flux due to a Phazon meteor impact; the third had the Space Pirates launch an all-out war against The Federation, an act which brought to light the source of all Phazon.
 * Touhou is currently in a Myth Arc, informally dubbed "Kanako Saga", starting with said goddess' arrival in Gensokyo in Mountain of Faith. Since then Kanako always have some influence in the story, usually related to her bid for power and Yukari's attempts to foil her plans. Prior to this each games were only loosely connected (if at all).
 * In place for the "Modern Warfare" trilogy, about Soap's rise, adventures,  The entirety of Call of Duty will become this if there's the possible Black Ops-Modern Warfare crossover hinted at by intel at the end of Black Ops.
 * The Mass Effect series is essentially one big story arc concerning the Normandy's battles against the Reapers with a bunch of little subplots and side stories tossed in between such as the Quarian/Geth war, Cerberus and their schemes, and the increasing bigotry amongst the various races of the universe.

Web Comics

 * Abstract Gender: Who experimented on Ryan and Brian and why? Unfortunately, the series ended before this question was answered.
 * Cest La Vie where one of the two original protagonists met her "true love" http://www.gocomics.com/cestlavie/2003/11/28 three days before http://www.gocomics.com/cestlavie/2003/11/25 and almost 8 years later, still has only had a few cups of espresso with him (other than trying to kill him with a teddy bear).
 * Girl Genius, starting with the fourth strip and continuing until today -- and likely quite some time into the future as well.
 * Girl Genius started as a comic book series, so that "fourth strip" is actually the fourth page of the first issue.
 * Tons in El Goonish Shive, the early strips are packed with many clues for later arcs. In a more specific sense, Lord Tedd and Tedd's backstory.
 * Somewhat subverted in that the creator admits that he has thrown out much of the earlier foreshadowing as irrelevant to the ever-changing 'current' direction of the strip.
 * It may take some time to notice, but Schlock Mercenary has a slowly building plot winding through most of its stories, All starting with Kevyn's invention of the teraport.
 * Gunnerkrigg Court initially seemed to be a series of one-shot stories. However, by chapter 7 it had became apparent that continuity is in full effect and that prior chapters had far-reaching, unforeseen consequences. When asked how much of the comic he plans in advance, Tom Siddell has said he scripts the plot many months in advance, and he knows exactly how the comic will end... but how he'll get from the former to the latter is up in the air.
 * Shadownova. Things are put in motion from the first page of the first chapter when a bad guy decides to bomb a school, leading to Iris's involvement in the human/everto war and subsequently the plot.
 * Order of the Stick, started with jokes about the Dungeons and Dragons rules, but soon developped a quite complex myth arc.
 * The Snarl: from the earliest chronological strip to present day, the whole strip is about dealing with it. Also, Xykon was revealed in strip 13, and, as of 832 shows no sign of being resolved any time soon.
 * It takes a while, but Sluggy Freelance's Myth Arc begins with Oasis and the plans of Hereti-Corp. There are a lot of other smaller arcs in the series, but the Oasis/HC arc has been going on in both the background and foreground for more than a decade. Not only that, but other major arcs, including, are being vowen together with it; if they all become one Myth Arc, it will have been going on (at least retrospectively speaking) practically since the very beginning.

Web Original

 * Kate Modern, though whether they manage to resolve it before the show ends remains to be seen.
 * Broken Saints
 * Some would argue that this is where Red vs. Blue has progressed towards, primarily involving Project Freelancer.
 * Main series of Chaos Fighters.
 * Marble Hornets is one big storyline involving Jay's attempts to figure out what happened to Alex, who the Operator is, and how the Masked Men and totheark are linked to him.

Western Animation

 * The point of Danny Phantom -- according to the fans, anyway. Although it's hard to tell after season 2.
 * Avatar: The Last Airbender: the Avatar mastering Water, Earth, and Fire, and saving the world.
 * Avatar, being heavily inspired by Japanese anime, alternates one-shot episodes with story arcs, although many one-shot episodes still contribute significant characterization.
 * Iron Man: Armored Adventures is a rare superhero cartoon example of where there's a set goal form the very first episode the heroes are trying to obtain, and all the following episodes develop towards that goal in one form or another.
 * The French cartoon Les Mondes Engloutis ("The Engulfed Worlds" in French), translated as Spartacus and The Sun Beneath The Sea in English, centered around the protagonists' search for a way to keep the titular Sun from dying and destroying the underground civilization of Arcadia. The show lasted only two seasons, and was ended when the heroes eventually discovered the truth behind the Sun and what was needed to save the people of Arcadia.
 * Justice League Unlimited had the Cadmus arc, which involved quite a bit of Arc Welding from the second season episode "A Better World," as well as two episodes from Superman: The Animated Series, which had originally aired eight years prior. The writers hadn't originally planned for it, but were able to make it work spectacularly well.
 * Sym-Bionic Titan appeared to be this, having little bits of information revealed at a time in non-chronological order, which makes it rather irritating that the complicated plot they got going is being wrapped up hastily in four episodes, due to cancellation.
 * Pirates of Dark Water did this all the way back in the 80s, with the entire series focused on obtaining the Thirteen Treasures of Rue to stop the titular dark water. Sadly, it was before it's time and was canceled before even half the treasures were found.