Saved for the Sequel

Tank: If the war was over tomorrow, Zion’s where the party would be.
Neo: It’s a city?
Tank: The last human city.
Neo: Where is it?
Tank: Deep underground near the Earth’s core, where it’s warm. You live long enough, you might see it.

— The Matrix^note Zion never appears in this movie but is one of the main settings for the two sequels, The Matrix Reloaded and The Matrix Revolutions

A plot element that doesn’t get fully developed, perhaps on the assumption that they’ll have the sequel to take care of it. The element can be a relationship, a theme, or a character that clearly has a lot more possible development, but doesn’t get it. The central plot is no less complete and these aspects may have just been there to enlarge the universe, but they're there and available for later use — more story to tell later. This can backfire if the sequel doesn't get made.

Compare Sequel Hook, which only occurs at the end of the story and is specifically geared toward inviting a sequel; Sequel Adaptation Iconic Villain, in which a famous villain from the hero's Rogues Gallery appears in the sequel; Development Gag, where hints of certain pathways the story could have taken are left as tidbits; and Refitted for Sequel, where an element is dropped from the original production only to be modified to fit a later work. Resolved Noodle Incident is very similar, except that does not require the follow-up to be an official sequel, or for it to be planned originally.

The mouse in What Happened to the Mouse? can seem like one of these, but unlike a mouse, something that has been saved didn't disappear, it just wasn't resolved— it is still present.

When this happens excessively, this will develop into a Kudzu Plot.

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Examples:

Anime & Manga

• Arachnid gets an ending with little closure for Alice and several loose ends including an Uncertain Doom for multiple characters. Years later the sidestory Caterpillar revealed the survival of its protagonist Imomushi and the plan to turn Alice into a new Shadow Dictator. The 2020 sequel named Blattodea then details what happened to Arc Villain Dinoponera after she was dropped out of Arachnid from being raped by a zombified mob, letting her recover and become friends with the new protagonist Chiyuri.
• Reinforce Zwei of the Lyrical Nanoha series. During A's she was the very definition of Last Episode, New Character; she only had a single line at the very end of the last episode of the season. Come StrikerS onward however she gets considerably more characterization and screen time.
• Nagisa Momoe, the Magical Girl form of the witch Charlotte/Bebe is introduced in Puella Magi Madoka Magica The Movie: Rebellion. Despite the hype for her appearance and her prominent placement in advertisements for the movie she gets very little characterisation or build-up compared to the other magical girls. Word of God says that if they ever do make a sequel to Rebellion they intend to do a lot more with her character. It wasn’t until Magia Record that we learned more of Nagisa's story.

Comic Books

• The Adventures of D & A: Doctor Feral, the Ultimate Machine, the Dollmaker, and the Prattler were mentioned in an Info Dump in the third story, and were ostensibly going to be used in future stories, but this ultimately didn't happen as this ended up being the comic's last story.

Films — Animation

• Near the beginning of Frozen (2013), Elsa and Anna's parents die in a shipwreck in a stormy sea. Frozen II confirms this this body of water indeed leads to Atahollan.
• Po's origins in the first Kung Fu Panda. It looks like we're going to find out toward the end of the movie, but then that turns into The Unreveal. It ends up becoming the premise of the sequel.
• The Super Mario Bros. Movie noticeably excludes many characters from the games, such as Yoshi (the green one), Princess Daisy, Wario and Waluigi, Bowser Jr. and the Koopalings, Toadsworth, Toadette, King K. Rool and the Kremlings, Professor E. Gadd, Rosalina and the Lumas (aside from Lumalee), enemies such as Lakitus (though Spinies still appear), Wigglers, Boos (aside from a cameo of King Boo), Thwomps, among many others. And in The Stinger, we see Yoshi begin to hatch from his egg...

Films — Live-Action

• Despite originally being touted as the "secret origin of Spider-Man", The Amazing Spider-Man left a lot of unanswered questions about Peter's parents and the nature of their experiments, which were finally addressed in The Amazing Spider-Man 2.
• Likewise, The Amazing Spider-Man 2 doesn't really resolve the situation with Harry's condition, and only introduces the Rhino for a Sequel Hook concerning the Sinister Six.
• Marvel Cinematic Universe:
  • A deleted subplot from The Avengers focusing on Captain America's attempts at rebuilding his old life (which ended up only alluded to) was included in Captain America: The Winter Soldier.
  • In Iron Man, Rhodey looks at the silver prototype Iron Man suit and says, "Next time, baby." Unintentionally funny in that Rhodey had been recast by the next film where he actually gets to wear the armor.
  • Early drafts of the script for Captain America: The First Avenger had Baron von Strucker as a side villain working under the Red Skull, the film's Big Bad. The writers felt that using Strucker in such a minor role would be a "waste," so they wrote him out. He eventually made his debut in The Stinger of Captain America: The Winter Soldier, and was used briefly as one of the villains in Avengers: Age of Ultron.
  • According to Joss Whedon, an amazingly awesome, fist-pumping Hulk moment from the climax of Age of Ultron was cut for disrupting the flow of the finale. He cited this trope as his reason for not revealing what it was, since Marvel can use it in a future film.
• Batman Begins is an excellent example. When it ended, the plot was resolved, but there was unresolved romance between Bruce Wayne and Rachel Dawes to provide fodder for the next movie.
  • The film also ends with a teaser involving the first known crime of The Joker, who would then become the Big Bad of the sequel.
• Denis Villeneuve's two-part adaptation of Dune, Dune: Part One and Dune: Part Two:
  • The Sand Worms are alluded to a lot over the course of the first movie and while some attacks of them are shown, they are mostly hide in the sand and just the fangs or head are revealed. The full sight of the worms is saved for the second film.
  • Feyd-Rautha Harkonnen, Emperor Shaddam IV, Princess Irulan and Lady Margot Fenring were also saved for the second film.
• This is attempted with Humma Kavula in The Hitchhiker's Guide to the Galaxy (2005). The Point of View Gun was clearly setting up a plot where he tries to brainwash everyone in the galaxy and take Zaphod's place. Too bad there won't be a second movie to make these things worthwhile.
• The Phantom Menace and Attack of the Clones ended with several plot points dangling to be picked up in the next installment. Technically, even the last movie of the prequel trilogy, Revenge of the Sith, ended with dangling plotlines... which were already resolved in the original Star Wars trilogy.
  • In The Force Awakens the fate or identity of Rey's family is never revealed, but it was suggested this would be important later on. In The Last Jedi, they have been revealed by Kylo Ren to be nobody important - drunkards who sold their daughter for drinking money and abandoned her on Jakku. Which was then backtracked in The Rise of Skywalker when it's revealed that she's the granddaughter of Emperor Palpatine, and her parents sold her to keep her hidden from him.
• In TRON: Legacy the son of the bad guy from the original TRON, played by Cilian Murphy, appears as an Encom board member, but does little save prove his technical savvy and quick mind. With his connection to the history of Tron and the plans for a third movie, it seems likely that he was there to foreshadow a larger role in that plot.
• In Superman: The Movie, General Zod is roaring to Jor-El, "You will bow down before me, Jor-El! Both you and, one day, your heirs!" However, he is then cast into the Phantom Zone and we have to wait to the next film to see him carry out that threat.
• Green Lantern (2011) has Sinestro, traditionally Hal Jordan's Arch-Enemy as a fellow member of the corp. While this fits in with comics continuity, one gets the feeling that this wouldn't be the case if Warner Brothers wasn't hoping to make it into a franchise.
• G.I. Joe: The Rise of Cobra is, of course, the story of the rise of Cobra. So Cobra Commander doesn't become Cobra Commander until the last couple of scenes, setting up the sequel G.I. Joe: Retaliation.
• Borderline example in The Hobbit, which includes some of the retcons and context that in the original books were included in the sequel The Lord of the Rings. It sort of fits in this trope because unlike the books, The Lord of the Rings movies were made first, and The Hobbit movies are effectively a prequel.
• Averted in the first Terminator. There were a couple scenes filmed in which Sarah discovered SkyNet's origins in Cyberdine and suggested to Reese that maybe they should try to destroy it to prevent the future war as well as a longer ending in which it was revealed that Cyberdine picked up the destroyed Terminator chip and arm, both setting up events that would occur in Terminator 2: Judgment Day. James Cameron ultimately had these scenes cut. (Though the sequel still used these ideas)
• The Golden Compass omitted the scenes at the end of the novel on which it is based, in which Lyra inadvertently betrays her best friend to her father and costs the boy his life. We should theoretically have seen those at the start of The Subtle Knife. Then the whole thing fell through.
• Although the Mutos of Godzilla (2014) were introduced as Canon Foreigners rather than updated versions of classic Toho monsters in order to give the film a bit more narrative freedom, Gareth Edwards has jokingly stated that he is contacting the casting agents of creatures like Mothra and King Ghidorah so that they can appear in sequels.
• The character of Gambit has been hit by this several times. He was originally intended to make a cameo in X2: X-Men United, (he ended up just being a name on a computer screen) but it was decided to save the character for X-Men: The Last Stand. After being written out of that film as well, he finally appeared in X-Men Origins: Wolverine. After that film was declared Canon Discontinuity, there were plans to re-introduce Gambit in X-Men: Days of Future Past, which also failed to materialize. He's was also set to appear in X-Men: Apocalypse, played by Channing Tatum, but failed to appear there as well.
  • Jubilee got hit with the same thing. She was originally supposed to appear in Days of Future Past as one of the future X-Men, but was cut for unknown reasons. She'll instead be used in Apocalypse as one of the new recruits, but doesn't actually get to do much in the plot..
  • The Stinger of Deadpool has Wade telling the audience that Cable is planned for the sequel, and he is one of the central characters of Deadpool 2.
• Transformers (2007) initially actively intended to have Soundwave as he is one of the staple Decepticons. However, ultimately the creators were unable to settle on a way to portray him right, so he was left for the sequel. His personality as a diehard loyalist of Megatron was still adapted into Blackout, and his role in the story ended up filled by Barricade and Frenzy.

Literature

• In the first Anonymous Rex book, Vincent's partner has been killed, leaving him a cynic, but how it happened is left unsaid. The second book is a Prequel where at the very end the death happens.
• Brandon Sanderson says that he has many developments in BioChroma that he plans to put into a sequel to Warbreaker named Nightblood. However, he is not entirely clear on if he will actually write it, and it has been put on hold until after he establishes his The Stormlight Archive series in the same Verse.

Music

• Queen's "Seven Seas Of Rhye" appears as an unfinished excerpt on their first album, and a full song on their second.
• Wham! left "Careless Whisper" off their first album Fantastic because it was felt to be too mature for the image the band was developing at the time. It therefore appeared on their follow up, Make It Big, though the original plan was to release it as a between-albums single (the recording of which wasn't to their satisfaction). In the UK, the single release was credited to George Michael exclusively, although it wasn't his true first solo single (that being "A Different Corner", released whilst the band was on hiatus).
• Yellow Magic Orchestra's "You've Got To Help Yourself" appears as a 30-second "preview" on Naughty Boys; the full song would first appear on the Remix Album Naughty Boys Instrumental before the band put out a vocal rendition on Service later that year.

Video Games

• The $30 expansion for Saints Row: The Third titled Enter the Dominatrix (originally thought to be an April Fools joke, but later revealed to be real) was announced to be canceled but later released for the next game.
• During the final mission of Star Fox: Assault, the Star Wolf team (who are allies to the Star Fox team for the moment) draw off the enemy ships pursuing the Star Fox team, allowing them to reach the game's Final Boss, and are not seen again, leaving it unclear whether they survived. There has been another game released in the series since then and all three members of Star Wolf did appear, confirming that they did survive, though there is ongoing debate among the fandom over whether that game is canon or not.
• BlazBlue: Calamity Trigger does not explain what exactly happened to Arakune, why Litchi is so bent on rescuing him, what Hazama is up to, who he works for, why Carl is looking for his father, what "Amaterasu" is, who the other five of the Six Heroes are, among many other plot details, creating a Mind Screw in general. BlazBlue: Continuum Shift, the sequel, answers these questions and brings up more. For instance, now that we know Carl is looking for his father because he's an absolute scumbag, we learn that he is a Chessmaster villain but nothing about what he wants or what he intends to do. Arakune is regaining sentience, but Litchi is about to do to herself what Arakune did before. Bang has the power to close portals to The Edge but has yet to have an opportunity to use it. And so forth.
• Mass Effect 2:
  • The quarians are worried over a remote star dying far faster than it ought to be. Tali hypothesizes it's due to dark energy affecting the interior of the star, but remarks that no race has the ability or any particular motive to destroy one. Nevertheless, she voices concern over the possibility of an adversary powerful enough to take a star out. The explanation is left open for Mass Effect 3. This ended up as an Aborted Arc - it's one of the few dangling threads that isn't addressed at all (not even in one of Shepard's emails).
  • Originally this was supposed to be the motive for the Reapers. They were intended to be interested in stopping the spreading of Dark Energy before it could tear the universe apart. And the key to this was biotics. This was replaced with the ending of the entirety of the story being about the Reapers as a Rogue A.I. Given the level of reception of the ending, it seems that this could have been better, though that is likely just because the current ending is so unpopular.
• Pokémon:
  • Pokémon Black and White left a number of loose ends that weren't wrapped up when the story was finished. Fans were expecting a "Grey Version" following the pattern from past generations, but instead full sequels were released: Pokémon Black 2 and White 2.
  • Pokémon X and Y had Zygarde as a Giant Space Flea from Nowhere, along with two unused moves in the games' code. There were plans to release another pair of Kalos games with Zygarde as the version mascot, but they were ultimately shelved, so the the anime was used to introduce new Zygarde forms. Meanwhile, the games wouldn't feature them until the next Pokémon generation, where Zygarde was featured as a sidequest, and was given the unused moves.
• The PlayStation version of Soul Edge, known outside of Japan as Soul Blade, was intended to feature certain characters as guest characters but in the end there wasn't time to implement them. Among these guest characters would have been Arthur, Kathandra and Monkasei. Arthur would appear in Soulcalibur as an optional replacement for Mitsurugi in Arcade machines (mainly for the Korean market but available in American ones too). Kathandra would be renamed to Cassandra and first appear in Soulcalibur II. Monkasei would be reworked into Yunsung and also first appear in Soulcalibur II (with his name instead being spelled as Yun-seong from III onward).
• Sonic the Hedgehog:
  • Due to Sonic 3 & Knuckles being split in two parts because of time constraints, most plotlines, the second half of the story, and most (if not all) of the Sonic & Knuckles content ended up becoming this.
    • Flying Battery was originally going to be a Sonic 3 stage placed between Carnival Night and IceCap, but they choose to save it for Sonic & Knuckles, feeling that this one would be too short otherwise.
  • Hidden Palace was going to be a hidden Sonic 2 stage where Sonic would gain his Super form after collecting all Chaos Emeralds, but it had to be scrapped due to time constraints. Two years later, the stage was incorporated into Sonic 3 & Knuckles, albeit using different layout, graphics and music, but keeping its concept, function (replacing Super Sonic with Hyper Sonic) and lore (albeit altered to fit with the game and the established canon), even making the stage more of a pivotal element in the story. Eventually, the 2013 mobile Sonic 2 port added back the Zone as an extra bonus, but it stripped it off its planned functions, lore, music and layout, and changed it into more of a prehistoric-themed stage to differentiate it from the S3&K incarnation.
  • The Japanese Sonic 3 manual mentions a legend described in the Chaos Emeralds' altar predicting the coming of a legendary dragon that would bring great disaster, and level concept art briefly seen in a special promoting the then-upcoming Sonic & Knuckles depicts Super Sonic fighting a dragon-like monster in space, implying that it would have been a boss battle. Sure enough, S&K's final level consisted in a battle in space as Super Sonic. However, the boss there was another of Eggman's mechs instead, and there were no more mentions of the dragon — when we visit Hidden Palace (the location of the Emeralds' altar), we only get to see a mural predicting the final battle with Eggman. The plot point would be finally addressed and resolved in Sonic Adventure with the introduction of Chaos, a legendary ancient monster that has a connection to the Chaos Emeralds and a dragon-shaped ultimate form, which indeed serves as the True Final Boss fought as Super Sonic (albeit with the setting relocated to a city in ruins).
• Some elements of Warcraft II's backstory (especially concerning the different human factions) weren't seen in Warcraft III, but returned with a vengeance in World of Warcraft.
• In the first Yakuza game, the Omi Alliance is mentioned in passing as a rival yakuza clan operating in Kansai, but other than Terada and a few goons, they have little real impact on the Tojo civil war. The rivalry is explored more fully in Yakuza 2, where the Omi takes the role of the main antagonist as they try to push in on the weakened Tojo Clan's territory, which gets further expanded on in both subsequent Like a Dragon games, as well as the Yakuza Kiwami 2 remake.

Web Original

• In Noob, Omega Zell and Gaea were meant to both have something big happen to them at the end of Season 5, which was supposed to be the last of the webseries. Part of Season 5's production ran concurrently with a crowfunding campaign meant to finance a movie that would be a sequel to the webseries. When the crowdfunding turned extremely successful, the creator decided to move these big moments to Noob: Le Conseil des Trois Factions so they could be made more impressive than if they had happened during the webseries.

Western Animation

• The Legend of Korra has this to a smaller extent in the form of Kuvira, who appeared briefly in the finale of Season 3 (with a very noticeable character model and soundtrack, mind you) before returning with a much larger role in Season 4.
  • It also addresses the issues of the extinct airbenders and Air Nomads caused by the Fire Nation in the original show with the restoration of the Air Nomads by the newly established Air Nation thanks to Harmonic Convergence.

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