Continuation

A Fanfic that picks up where a series, movie or book left off and carries on from that point. Frequently seen for television series or Anime that were cancelled before they could complete their Story Arcs, or which concluded with deliberately ambiguous endings, or whose author died with the series still incomplete. Frequently written in order to provide a much more satisfactory ending than the one provided by the original writer(s). May also occur for a series that lacks a distinctly defined ending, though in that case it doesn't much matter whether a story is set during or after a series (unless it's so long after that the characters have significantly aged or otherwise changed).

The inevitable response to the human need to ask, "and then what happened?"

See also Next Gen Fic, which is set way after the series ended.

Anime & Manga

 *  In The End by V0ID starts seconds after the ending of Code Geass. It fills in some of the moments that went unexplored, and continues on to the chain of events following the last episode.
 * Another series, The First Servantby Firelord Zuko starts off a few years after the ending, mainly through the eyes of Nunnally's son and heir, Faramond vi Britannia, though it spans several more decades. The story itself also fleshes out the universe (including scenes set in the EU) as well as the fallout of Zero Requiem on the world stage.
 * Earth by Ken Wolfe picks up at the end of the El-Hazard: The Magnificent World OVAs and spins an epic tale that not only cleans up the few loose threads left by the series, but also accounts for all of the pastel drawings of "things that happen after" shown under the end credits for the last episode!
 * Richard Lawson's Thy Inward Love starts off at the irritating no-ending ending of the Ranma ½ manga and provides a conclusion that is much more fulfilling to the reader.
 * Likewise, Vincent Seifert's The Taming of the Horse.
 * The Neverending Road is an absolutely brilliant Hikaru no Go Fanfic that begins right where the manga abruptly ends.
 * The number of Yu-Gi-Oh! fanfics of this type is staggering -- and the release of its sequel series, Yu-Gi-Oh! GX, did nothing to slow it down; instead, authors have either focused on filling in the ten-year blank between series or moved even further ahead.
 * Due to the ambiguous ending of the second Cardcaptor Sakura movie, when, many fan authors felt the need to clarify what else happened. This has led to a number of continuation fics, many of which involve new cardcaptors (who may or may not be self-inserts) picking up where Sakura left off, and an incredibly popular obsession with Alternate Universe romance fics whose only basis of being part of the canon is that the guy is "Syaoran" and the girl is "Sakura", and they may or may not have friends or relatives with familiar names from the series.
 * When the original Tenchi Muyo! OVA series (actually two series of 6 episodes each, plus a special episode between them) ended in 1995, little had been resolved. While the first OVA was entirely workable as a standalone story, it was blatantly obvious that the second was intended to lead into something bigger. Various supplemental material made this even more obvious. But it didn't happen, and two Alternate Continuity television spinoffs were produced instead. The second spinoff was pretty much a flop, and aside from a Magical Girl parody series and The Movies that was pretty much the end of Tenchi Muyo!. Thus, assuming the story would never be completed, fanfic writers naturally took it upon themselves to make their own endings. The majority of Tenchi fanfics seem to have been Continuations of the OVA storyline, while the remainder was filled mostly with similar fanfics for the first TV series (which had a non-ending in its own right). Then a decade after the franchise had seemingly died, a third OVA series materialized. But it didn't really advance the story much anyway, aside from introducing several new characters; all the major events never really happened. Thus, Continuations are still common, but their writers have to either set them after the non-events of the third OVA, or perhaps more frequently just ignore it because it sucked.
 * Samurai Champloo has spawned a number of fics based on what happened after the trio split up.
 * Thawing Permafrost is a Rosario + Vampire fic set three years after the end of Season I, after the main cast has graduated from Yokai Academy.
 * Epilogue of Evangelion is a 700-page (non-hentai) Doujinshi following Shinji and Asuka's life after End of Evangelion. It's also crammed with WAFF and of course.
 * The Death Note fanfiction Kira Is Justice is set four years after the series. (See its trope page here.)
 * There is a similar fanfic to the above called Ryuk Returns, set five years after the series (which also inspired the above).
 * And yet another one: Life After Death Note.
 * The Magical Girl Lyrical Nanoha fanfiction MGLN Crisis here is set one year after the third anime season. See its trope page here.
 * The Elemental Chess Trilogy returns the reader to the world of Fullmetal Alchemist, beginning almost three years after the Promised Day and concluding roughly five years farther on.
 * Rebellion definitely seems to pick up right after the last episode of the Anime for Chobits.
 * A lot of Naruto fanfics take place after the events of the manga ended; not quite Next Gen Fic for some. White Rain is a very good example.

Film

 * The film The League of Extraordinary Gentlemen was of variable popularity with fans of the graphic novel, but among those who enjoyed it, there developed a large number of 'what happened next' stories. Most of these involve adding characters to the League with powers that weren't already part of the cadre, such as werewolves or psychics. At least one series, however, subverted the tendency by saddling the League with an individual completely lacking in supernatural abilities.
 * A rather sizable supply of Kung Fu Panda fiction focuses on what happens afterward. An unsurprisingly large amount of it is Tai Lung fixfic.
 * WALL-E has many minor continuation fics, but the WALL-E Forum Role Play really stands out.
 * Even though a sequel to The Dark Knight is already in the works, a fanfic sequel was already written here. Of course, considering Heath Ledger is no longer with us and both Nolan and Bale have gone on record to say that no one will reprise the role of Joker, this fic will continue to utilize this trope.
 * Pretty much every Labyrinth fanfic is this, even before the official sequel came out. Numerous examples double as fixfics where Sarah "was too young to understand what Jareth was offering her and regretted her decision".
 * Continuing with David Bowie films: There aren't near so many of them, but there's a good chance a fanfic for The Man Who Fell to Earth will take the story beyond the Downer Ending in some way.
 * Guest from the Future 2 is set a few years after Guest From the Future.
 * The Fall of San Franciscois a The Good, the Bad and the Ugly fic that picks up some forty years later, with Tuco as a rich old man living in San Francisco during the quake of 1906.
 * Although it was deliberately obscured in the promotional material issued before its release, Tim Burton's 2010 version of Alice in Wonderland was actually a Continuation of the original books in the grand fanfic tradition.
 * A number of fan-made continuations exist attempting to pick up on the ambiguous ending of John Carpenter's The Thing. One particularly noteworthy story is Unfinished Business, which attempts to connect both the 1982 film and the prequel, and opts for a more optimistic tone despite the dark nature of the stories it was based on.
 * About 75% of Tron fanfic deals with the aftermath of Tron: Legacy.

Literature

 * Animorphs, which ended with ramming the Blade Ship into the One. Apparently Ramming Doesn't Always Work for some readers.
 * The epic poem The Aeneid ends with Aeneas killing his nemesis. Many felt that the ending was incomplete, and in the 15th century, an Italian poet named Maffeo Vegio wrote a continuation for it, which was widely printed in later editions. The Aeneid, of course, follows the adventures of a minor character from The Iliad sometime after the fall of Troy. It could be considered a continuation fic itself.
 * One of the primary reasons Cervantes wrote Part II of Don Quixote was that so many people wrote Continuations of the original that were, in his opinion, Completely Missing the Point of said original.
 * Harry Potter: It's a fairly popular genre in the ficdom now, either with those who support the canon pairings or those who, well, don't.
 * Weirdly, there are those who accept the Epilogue rather than label it as non-canon, while still writing fics where their preferred couple get together. This leads to bizarre results where Harry decides after twenty years he doesn't really love Ginny after all, and spontaneously gets together with Hermione, who has likewise realised the magic's gone out of her marriage with Ron. Ultimately everyone's okay with it and it's all happy families and Babies Ever After. In other cases it turns out that Ginny was dosing Harry with love potion and Ron is a violent rapist, and the two find comfort in each other's arms. Usually there is some retaliation.
 * After John Polidori's vampire tale "The Vampyre" was adapted into a French stage play by Charles Nodier, an unauthorized sequel novel by Cyprien Bérard, Lord Ruthwen ou les Vampires (1820), was attributed to Nodier.
 * Prior to the prequels, most of the Star Wars Expanded Universe was a continuation from the original trilogy.

Live Action TV

 * When Buffy the Vampire Slayer ended, countless virtual series popped up in its wake. The majority of these took the Scooby Gang to the Cleveland Hellmouth. These were, ironically, Jossed by the new season of Angel and the new season of Buffy, in comic form. These tend to phase out characters who are disliked or a challenge to write dialogue for. The absence of such characters are usually explained away as them having left to fight demons elsewhere; if they appear at all, it's only in phone calls where their end of the conversation isn't heard.
 * The site Virtual Mutant takes this to an extreme. Beyond giving both Buffy the Vampire Slayer and Angel two additional seasons and a feature film adaptation each (all their stuff is written in screenplay form), it has a total of six additional spinoff series, and eventually grew into a site for dozens of fanfic and original virtual series. Furthermore, the site runners have identified specific actors to play the new characters -- particularly important for the spinoffs, where most of the characters never appeared in the original canon series. One could imagine that Virtual Mutant series were produced in an alternate reality where Mutant Enemy became a network in its own right.
 * Charmed got two more seasons on charmed-net.de. While the site has been closed after 10 years all scripts are still available. Surprisingly it takes the not so popular Post Script Season and turns it into something really enjoyable.
 * The folks at stillflying.net took a rather unique approach, continuing from the end of Firefly in which the remainder of the first season and the first half of the second is a buildup to the events of the film Serenity, and the second half of season two is the events of that film with much more room to dig into the characters and flesh out the story. They also plan to continue into season three.
 * The Firefly fanfic Forward is a continuation of the series set after the end of Serenity, though it is partially alternate universe, in that.
 * Post-Miranda fic is very common in the Firefly fandom nowadays.
 * Almost every single fanfic for The Sarah Connor Chronicles released since its cancellation has been a continuation, with most opting for a Fix Fic approach with John getting together with Cameron.
 * Several JAG fanfics take place after the series finale, including Life for a Life, The Cabal, and Face On the Milk Carton.
 * Forever Knight got two fanfic virtual continuations: FK4, a Script Fic series which retconned the Downer Ending, and V4S, a prose series that took the ending as canon and continued in a darker vein.
 * The Tenth Kingdom has one in the fanfic Reality.
 * "Post-Gauda Prime" has been a Blake's Seven staple for 30 years now, postulating that the crew was shot with stun guns, that it was some kind of loyalty test, or that it wasn't Blake that got shot at all.

Video Games

 * Go Not Gently continues the story of Final Fantasy IX so deftly, and with such thematic follow-through, that you'd wish it was canon if it wasn't so sad.
 * Several fan fictions based off of 'Mother 3'' focus on after Lucas . Most of these relate to the main cast while others touch on the characters' relationship(s) with each other, such as Kumatora's friendship/relationship with Lucas or Duster. A couple have involved.
 * There are also a few that take place between Earthbound and Mother 3 in which either Pokey/Porky returns to cause trouble or Giygas is revived. Even fewer take place between EarthBound Zero and Earthbound to explain what happens between that small time period between those games.
 * Parallel Symphony is one of many fanfics that pick up after The Legend of Zelda Ocarina of Time, in this case telling the tale of.
 * Also in the universe of The Legend of Zelda Ocarina of Time is The Legacy of Hyrule, which picks up with the sages, three years after the end of the battle with Ganondorf.
 * The Count's World is a Super Paper Mario fanfiction series that picks up after the game ends and continues in the style of a Saturday Morning cartoon. It explains away some of the ending . Rather than existing for the purpose of tackling unanswered questions or elaborating on the story, it mainly focuses on the characters trying to make the world a better place, getting into odd situations along the way.
 * Irya Sheen Ace Attorney is made as a continuation of the Ace Attorney series.
 * Two Step is a Left 4 Dead fanfic that takes place after the ending to the sequel.
 * Twisted Fates takes place a year after Ghost Trick, and deals with Sissel trying to take on a Serial Killer

Western Animation

 * The Gargoyles Saga, which picked up where the series Gargoyles left off.
 * The Kim Possible fanfic community really blossomed into an all-out industry when the Grand Finale aired, with hundreds of stories picking up right after the junior prom, many very conscious attempts to be as Original Flavor as possible. Then the series was Uncancelled, and the vast bulk of those stories were contradicted by season 4. Now, after the new Grand Finale, it's all stating over again with a new crop of continuations, heading off to the college years and beyond.
 * Many Avatar: The Last Airbender fics are being written about the fate of Azula after she lost her mind. And Zuko's quest to find his mom. Maybe some stuff about the defeated firelord as well. Azula going mad and Zuko demanding his father for the location of his missing mother is a Plotbunny screaming, "WRITE ME, BITCH!"\\a good example of this is Where do we go from here. A 20 part story that is being written now. dealing with the first ten yeards after the end of the war. all the main character are used.
 * Azula Trilogy, intended as both canon compliant and Original Flavor (albeit somewhat darker because, well, Azula) picks up all these threads, especially Azula's
 * Danny Phantom also has quite a lot of this, jumping off from two timelines to make it even more complicated; usually it involves mishaps in Time and Space. Oddly enough, DP didn't leave any threads dangling and left very little to say "what then?" about. Which is probably a major contributor as to why the finale is so hated and people prefer to add on their own endings.
 * What about Valerie Grey? In the episode before Phantom Planet, she discovered that Vlad Plasmius and Vlad Masters were the same person, and vowed revenge as she flew away. Then she gets little more than a cameo in Phantom Planet, and seems to have nothing to say about the revelation that Fenton and Phantom are one-and-the-same. Fanfic Fuel, anyone?
 * Not to mention Dani Phantom...
 * There is a series of photocomics depicting events after the conversion of Cybertron at the end of Beast Machines. The series begins with a story entitled "Obsidian's Lament", which picks up with Vehicon generals Obsidian and Strika where the series left them, in orbit around Cybertron. From there it explores the effects of the reformatting on Cybertron and the population.
 * X-Men: Evolution has a large selection of "Season 5" stories on Fanfiction.Net.
 * Depending on how long it takes for a Total Drama World Tour postseason special to air, assuming it airs at all, we're going to be in for a lot of fanfics that cover the events of a final aftermath special. Which will all eventually be Jossed by the real special.
 * Most Galaxy Rangers fanfic is set after the series, and sometimes gets called "second season," especially if it's close to Original Flavor.