History AbortedArc / MarvelUniverse

* During the ''ComicBook/{{Inferno}}'' crossover, Mister Fantastic and the Invisible Woman helped form a new team of Avengers in a manner similar to the formation of the original team way back in ''ComicBook/TheAvengers'' #1. Despite clearly being positioned as major players in the new team, they were quickly written out of the book once ''Inferno'' ended. It turns out that this is because Creator/WaltSimonson had been given permission to add the two to the Avengers, only for editorial to change their minds and decide they wanted them back in the ComicBook/FantasticFour instead.

** [[CanonForeigner Aaron Reece]], aka Molecule Kid from the same-titled Season 1 episode. At the end of the episode, he (and Fury) are convinced that he should join up with Fury's SHIELD. Academy Hero Program, the same one that [[WesternAnimation/{{Ultimate Spider-Man}} Spider-Man]] is in. Despite him departing with Fury in the end, and despite a rather powerful and emotion-filled episode introducing the character, Aaron is nowhere to be seen or heard after the episode ends. Not even the 3rd and 4th seasons of ''WesternAnimation/{{Ultimate Spider-Man}}'' which expands the hero count and even shifts focus to the Academy's HQ [[WhatHappenedToTheMouse sees any hide or hair of Aaron]].

* ''WesternAnimation/{{Ultimate Spider-Man}}'': When the Lizard first appeared, a serum for scorpion mutations were seen as well. When the Scorpion finally appeared on the show, it was as as BadassNormal and later with a suit of PoweredArmor. At no point did he ingest or get his powers from the serum.

*** The even bigger plot thread was TheStinger that showed Thunderbolt Ross partnering with [[Film/IronMan Tony Stark]] to take down the Hulk. This was never mentioned in any of the subsequent films. [[OnceMoreWithClarity This was explained]] in the short film ''Film/TheConsultant''; S.H.I.E.L.D. sent Stark as a patsy to ruin the relationship with Ross after the World Security Council ordered Fury to add the Abomination to the roster of the Avengers.

*** Both in-universe and a meta example, despite it being a trademark of his backstory and one of the reasons the army is in the supersoldier business, Steve doesn't actually fight any Nazis, just in films and comic books. Justified since by the time he gets sent overseas and begins to take part in the war, Schmidt and HYDRA are much larger threats. Although material in Winter Soldier shows that the Howling Commandoes did missions against non-HYDRA soldiers.
** The New Avengers at the end of ''Film/AvengersAgeOfUltron'' were hyped up as a replacement roster because of Tony retiring, Hulk going missing and Thor leaving to look for the Infinity Stones. They proceeded to do one onscreen mission in Civil War which lead to the epynonmous conflict and then quietly disappeared until ''Film/AvengersInfinityWar'' 3 years later.

*** HYDRA agent Mitchell Carson got Pym particles in ''Film/AntMan1''. If he ever used them has never been addressed.

** Likewise, despite "Cold Comfort" having Cyclops and Havok puzzled by each other, including their powers not working, nothing is done with their rivalry or even that they're brothers.

** The same episode has the {{Time Travel}}er Shard say that Archangel is destined to become a member of the X-Men. Despite this, Archangel never actually joins the team in any of the subsequent episodes. This is because "Beyond Good and Evil" was initially going to be the show's GrandFinale, and was planned to end with the team's line-up shifting. When the show was [[PostScriptSeason unexpectedly picked up for one more season]], the scene showing Archangel and the other new heroes joining the X-Men was scrapped.

* ''Film/TheAmazingSpiderManSeries'': One of the many {{Sequel Hook}}s at the end of The Amazing SpiderMan involves Peter attempting to track down the man who shot Uncle Ben. In The Amazing Spider Man 2, this plot thread is never even mentioned. Likely this was meant to be continued in a future film, however with the series now canned so Spider-Man can join the MCU, it'll never be resolved.

* One of the many {{Sequel Hook}}s at the end of ''Film/TheAmazingSpiderMan'' involves Peter attempting to track down the man who shot Uncle Ben. In ''Film/TheAmazingSpiderMan2'', this plot thread is never even mentioned. Likely this was meant to be continued in a future film, however with the series now canned so Spider-Man can join the MCU, it'll never be resolved.

* Jonathan Hickman's ''Fantastic Four'' run ended with the adult Valeria Richards gaining access to the space between universes that the multiversal Council of Reeds used as their base of operations. It was apparently her plan all along to gain access to this space, and she states that now she can build, an ominous reference to Doctor Doom's previous failed attempt at godhood. While Hickman's ''Fantastic Four'' run led into his ''Avengers'' run in a big way and the multiverse is collapsing within that story, nowhere does adult Valeria show up again.

* At the end of the first arc in ''[[ComicBook/TheInvadersComicBook All-New Invaders]]'', ComicBook/TheEternals discovered a comatose ComicBook/{{Galactus}} in the Negative Zone (where he'd been trapped following ''ComicBook/CataclysmTheUltimatesLastStand''), and planned to use the Gods' Whisper to control him and make him destroy the Kree. The planned attack on the Kree never occurred, and Galactus later appeared without any reference to how he'd escaped the Negative Zone.

* At the end of the first arc in ''[[ComicBook/TheInvaders All-New Invaders]]'', ComicBook/TheEternals discovered a comatose ComicBook/{{Galactus}} in the Negative Zone (where he'd been trapped following ''ComicBook/CataclysmTheUltimatesLastStand''), and planned to use the Gods' Whisper to control him and make him destroy the Kree. The planned attack on the Kree never occurred, and Galactus later appeared without any reference to how he'd escaped the Negative Zone.

* During ''ComicBook/HeroesReborn''[='=]s "Industrial Revolution" arc's climax, ComicBook/{{Onslaught}}, the entity whose actions were the reason ComicBook/TheAvengers and ComicBook/FantasticFour were in that universe to begin with, briefly appeared in the reactor on Avengers Island as the Hulk sealed it off. Outside of Reed nothing that Onslaught was alive before he disappeared, nothing was done with it and ''ComicBook/OnslaughtReborn'' would tie Onslaught's return to the events of ''ComicBook/HouseOfM''.

* The "Home Schooling" arc of ''ComicBook/{{Runaways}}'' featured the Runaways' Malibu home being destroyed by a missile attack that also kills Old Lace, Klara going berserk, and Chase running away [[spoiler:and later getting hit by a car while chasing after a girl who looks like Gertrude Yorkes]]. It also revealed that the Runaways had been under surveillance by Chase's mysterious uncle, Hunter Stein. But the series was cancelled before the arc came anywhere near a conclusion, and when the Runaways finally resurfaced several years later in ''ComicBook/AvengersAcademy'', the only part of "Home Schooling" that was acknowledged was Old Lace's apparent death (which was quickly undone - the arc revealed that [[spoiler:[[Characters/{{Runaways}} Nico Minoru]] cast a previously-unmentioned spell that sent Old Lace into another world where she was restored to life.]])

* The "Home Schooling" arc of ''ComicBook/{{Runaways}}'' featured the Runaways' Malibu home being destroyed by a missile attack that also kills Old Lace, Klara going berserk, and Chase running away [[spoiler:and later getting hit by a car while chasing after a girl who looks like Gertrude Yorkes]]. It also revealed that the Runaways had been under surveillance by Chase's mysterious uncle, Hunter Stein. But the series was cancelled before the arc came anywhere near a conclusion, and when the Runaways finally resurfaced several years later in ''ComicBook/AvengersAcademy'', the only part of "Home Schooling" that was acknowledged was Old Lace's apparent death (which was quickly undone - the arc revealed that [[spoiler:ComicBook/{{Nico|Minoru}} cast a previously-unmentioned spell that sent Old Lace into another world where she was restored to life.]])

* During ''ComicBook/HeroesReborn''[='=]s "Industrial Revolution" arc's climax, ComicBook/{{Onslaught}}, the entity whose actions were the reason ComicBook/TheAvengers and ComicBook/FantasticFour were in that universe to begin with, briefly appeared in the reactor on Avengers Island was the Hulk shut it off. Outside of Reed nothing that Onslaught was alive before he disappeared, nothing was done with it and ''ComicBook/OnslaughtReborn'' would tie Onslaught's return to the events of ''ComicBook/HouseOfM''.

* During ''ComicBook/HeroesReborn''['=]s "Industrial Revolution" arc's climax, ComicBook/{{Onslaught}}, the entity whose actions were the reason ComicBook/TheAvengers and ComicBook/FantasticFour were in that universe to begin with, briefly appeared in the reactor on Avengers Island was the Hulk shut it off. Outside of Reed nothing that Onslaught was alive before he disappeared, nothing was done with it and ''ComicBook/OnslaughtReborn'' would tie Onslaught's return to the events of ''ComicBook/HouseOfM''.

* At the end of the first arc in ''[[Comicbook/TheInvaders All-New Invaders]]'', Comicbook/TheEternals discovered a comatose ComicBook/{{Galactus}} in the Negative Zone (where he'd been trapped following ''Comicbook/CataclysmTheUltimatesLastStand''), and planned to use the Gods' Whisper to control him and make him destroy the Kree. The planned attack on the Kree never occurred, and Galactus later appeared without any reference to how he'd escaped the Negative Zone.
* In ''Beyond!'', Creator/{{Dwayne McDuffie}} killed off the teen hero Gravity by having him perform a HeroicSacrifice. However, the final panel of the book hinted that this wasn't the end of Gravity's tale. The character was later resurrected in [=McDuffie=]'s ''Fantastic Four'' run, but hasn't really done anything of note since. It turns out that this is because the original plan was to resurrect Gravity and have him become the new ComicBook/{{Captain Marvel|l}}, but someone else decided it would be a better idea to introduce a Skrull posing as the original Captain Marvel in ''Comicbook/CivilWar'' instead.

** Reginald Hudlin's first run ended with Comicbook/ErikKillmonger's son swearing vengeance against T'Challa after watching Comicbook/MonicaRambeau kill his dad. The son hasn't been seen since then, and his planned revenge has yet to occur.

* The Sky-Walker from ''Comicbook/{{Daredevil}}'' was billed as "the most startling character in the annals of Marveldom" when he first appeared. He showed up in exactly one issue before completely disappearing. WordOfGod from Marv Wolfman is that he had wanted to use the character to set off a big sci-fi story, but by that point he'd become so unhappy with his tenure on the title that he asked to be taken off ''Daredevil'' and moved to another book.
* Creator/KevinSmith's infamous ''Comicbook/{{Daredevil}}/Bullseye: The Target'' mini-series, which was never finished. The first (and only) issue saw a group of Muslim extremists coming to New York to hire Bullseye to kill an extremely valuable target, for which he'd be paid 20 million dollars. It ended with him expressing surprise at the intended victim but then agreeing to do it anyway. We never found out who it was or what happened next, but WordOfGod is that the target would have been revealed to be ComicBook/CaptainAmerica.
* Creator/JonathanHickman's ''Comicbook/FantasticFour'' epic, ''The War of the Four Cities''. The four blocs are the Lost City of the High Evolutionary (tied to Silver Age villain the Mole Man), the floating city of the Universal Inhumans (tied to, well, Comicbook/TheInhumans), the hidden lives of the Cult of the Negative Zone (tied to Annihilus), and the Last Kings of Old Atlantis (tied to Namor the Comicbook/SubMariner)... who kind of... died suddenly. Presumably when Hickman realized that with Namor and the surviving Atlanteans living under [[Comicbook/XMen Utopia]] meant there was no way to hold the X-Men off until the GrandFinale. Never mind, we were then treated to the addition of the Kree to the storyline.
* The final issue of Creator/MattFraction's ''Comicbook/{{FF}}'' ended with the implication that Pym Particles could be used to resurrect Cassie Lang, Comicbook/AntMan's dead daughter. Cassie did end up getting resurrected a relatively short time later, but in a manner entirely unrelated to the plot thread from ''FF''.

* ''Comicbook/TheIncredibleHercules'' had a subplot where Comicbook/AmadeusCho visited his deceased family in the afterlife, only to discover that his little sister, whom he had presumed dead as well, was actually still alive. Maddy Cho did finally appear years later in ''Comicbook/TotallyAwesomeHulk'', but her actual reunion with Amadeus apparently took place entirely offscreen.
* Gerry Duggan's ''[[Comicbook/IncredibleHulk Hulk]]'' run ended before the plot about Gammon, Banner's [[AIIsACrapshoot evil A.I.]], could reach any sort of meaningful resolution. Earlier in the same run, there was also {{Foreshadowing}} for a confrontation between Doc Green and Kang the Conqueror. The anticipated fight never happened.
* During the ''Comicbook/{{Inferno}}'' crossover, Mister Fantastic and the Invisible Woman helped form a new team of Avengers in a manner similar to the formation of the original team way back in ''ComicBook/TheAvengers'' #1. Despite clearly being positioned as major players in the new team, they were quickly written out of the book once ''Inferno'' ended. It turns out that this is because Creator/WaltSimonson had been given permission to add the two to the Avengers, only for editorial to change their minds and decide they wanted them back in the ComicBook/FantasticFour instead.
* ''[[Comicbook/TheDefenders The Last Defenders]]'' ended with Kyle Richmond forming a new group of Defenders consisting of Comicbook/SheHulk, Son of Satan, Krang, and the new Nighthawk after learning from the time-traveling villain Yandroth that this team would go down in history as his greatest achievement and an important part of the Marvel Universe. Indeed, the last page had Yandroth ominously stating that these new Defenders were reality's greatest hope for survival. The new team only ever appeared again in the obscure mini-series ''Vengeance'' (where they weren't even the main characters), and then quietly disbanded offscreen. They certainly ''never'' did anything even remotely as important as the achievements Yandroth hinted at.
* A major part of Brian Bendis' short-lived ''ComicBook/MoonKnight'' series revolved around the hero finding a decapitated ComicBook/{{Ultron}} head, with the series' final issue promising that the plot point would be addressed in the then-upcoming ''Comicbook/AgeOfUltron'' crossover. Not only was the subplot about the Ultron head not resolved, but Moon Knight himself hardly appeared in the actual event.
* The final story arc of the original ''Comicbook/PowerPack'' featured the appearance of a mysterious homeless man known only as Mr. Raymond, who possessed fire-based superpowers and seemingly had some sort of connection to Frankie Raye. It was strongly implied that this was a grown-up version of Tommy "Toro" Raymond, the Golden Age Human Torch's seemingly-deceased KidSidekick, and that he was also Frankie's biological father (which would explain her powers). This plot thread was never continued, and later stories would definitively establish that Toro did indeed die for real back in ''Comicbook/SubMariner'' #14. In fact, Toro's resurrection was a major plot point in the later ''Comicbook/AvengersInvaders'' crossover.
* The "Home Schooling" arc of ''Comicbook/{{Runaways}}'' featured the Runaways' Malibu home being destroyed by a missile attack that also [[spoiler:kills Old Lace]], Klara going berserk, and Chase running away [[spoiler:and later getting hit by a car while chasing after a girl who looks like Gertrude Yorkes]]. It also revealed that the Runaways had been under surveillance by Chase's mysterious uncle, Hunter Stein. But the series was cancelled before the arc came anywhere near a conclusion, and when the Runaways finally resurfaced several years later in ''Comicbook/AvengersAcademy'', the only part of "Home Schooling" that was acknowledged was Old Lace's apparent death (which was quickly undone - the arc revealed that [[spoiler:Nico cast a previously-unmentioned spell that sent Old Lace into another world where she was restored to life.]])
* Creator/WarrenEllis' short-lived ''[[Comicbook/TheMightyThor Thor]]'' run introduced a subplot about Warren Curzon, a British cop who was investigating Thor. When Ellis decided to leave the title after the fourth issue, he had Enchantress casually kill off Curzon, making his whole storyline a ShaggyDogStory.

* Abnett's ''{{ComicBook/Nova}}'' run had an issue that ended with the return of AntiHeroSubstitute Garthan Saal with [[UnexplainedRecovery no explanation]] how he was suddenly BackFromTheDead. He hasn't appeared since.

* Near the end of Nick Spencer's ''Comicbook/SecretAvengers'' run, ComicBook/DaisyJohnson was fired from ComicBook/{{SHIELD}} and replaced by ComicBook/MariaHill. Johnson was later shown recruiting the [[ComicBook/BuckyBarnes Winter Soldier]] for a plot to bring down Hill's regime and expose her shady dealings to the public. The book quickly veered off course into a tie-in to ''Comicbook/{{Infinity}}'' involving one of the new [[ComicBook/TheInhumans Inhumans]], and abandoned the Daisy subplot before being cancelled. Other titles later established that Daisy and Maria had resolved their differences.

* In one of the issues of the ''Comicbook/{{Daken}}'' solo series, the title character reads a news article about the new ComicBook/CaptainAmerica being outed as ComicBook/BuckyBarnes, the man who killed Daken's mother. He's shown looking at Bucky's picture with an intense stare, and there is a strong implication that Daken is planning on confronting Barnes. The book was cancelled before this fight could occur and Daken never brings it up again in any of his appearances.

* The final issue of ''Comicbook/{{Dazzler}}'' ended with Allison seeking a new status quo, and Comicbook/{{Beast|Marvel Comics}} suggesting that she join Comicbook/XFactor, the new team he and several of his former X-Men teammates were putting together. Dazzler did not end up appearing in ''X-Factor'', as the plan to have her be the team's fifth member was changed when editorial decided to resurrect Comicbook/JeanGrey and have her be part of the group instead.

* ''ComicBook/NewXMenAcademyX'' looked to be building up a BigBad in [[MindRape mind-rapist]] Sean Garrison, the PsychoPsychologist father of one of the main characters, Wallflower. However, the original writers on the book were abruptly fired following ''ComicBook/HouseOfM'', and not only was this storyline never mentioned again, but Wallflower was killed in the wave of anti-mutant violence that followed said ''House of M''. The new creative team implied in an interview that Garrison was depowered by the Scarlet Witch's reality warp, but nothing definitive has ever been stated on his fate in canon itself.

* ''Comicbook/SpiderMan'':
** The infamous F.A.C.A.D.E. incident. Long story short, Terry Kavanagh introduced a new baddie named [[http://www.marvunapp.com/Appendix5/facadesman.htm F.A.C.A.D.E.]], and a huge deal was made about who he really was under the mask (well, [[PoweredArmor helmet]]). Unfortunately, '"Comicbook/TheCloneSaga" began right after F.A.C.A.D.E.'s debut storyline ended, so the mystery of his true identity has never been resolved. It's become sort of a RunningGag that whenever the character does appear or get mentioned, there's usually some sort of joke about his identity.
** Near the end of Creator/BrianBendis' tenure at Marvel, he began dropping hints that Comicbook/MilesMorales would be abandoning the Spider-Man name in order to step out of Peter Parker's shadow and create his own heroic identity. This, coupled with Comicbook/{{Cable}} commenting that Miles would have a future in espionage, led some to conclude that Miles would become a costumed spy of some kind (rumored to be named Spy-D). This was dropped after Bendis' departure, with the subsequent ''Miles Morales'' series by Saladin Ahmed keeping the character in his role as Spider-Man and focusing more on street-level heroics than spy stuff.

* ''Comicbook/UncannyAvengers''
** During the "Planet X" storyline, Comicbook/TheWasp and Havok had a daughter together named Katie while in the alternate future created by Earth's destruction. Katie was eventually kidnapped by Kang the Conqueror, who used her as leverage to get Havok to play along with his plans. Just prior to ''Comicbook/{{AXIS}}'', Immortus showed up and gave the couple hope by telling them they could get Katie back by conceiving a child at the right date and time, which he claimed would allow Katie to be reborn in the prime timeline. Both Wasp and Havok were written out of the series after ''AXIS'', and the subplot was later abandoned entirely once Remender left the book after ''Comicbook/SecretWars2015''. The romantic relationship between the two was also ended offscreen by subsequent writers, removing any remaining hope for Katie's rebirth.
** Rick Remender's run ended with Comicbook/TheVision learning a horrible secret about Comicbook/ScarletWitch and refusing to divulge it in order to spare her feelings, and the High Evolutionary claiming that his genocidal actions were meant to safeguard the world from some unspecified oncoming threat. Both plot points were dropped when the book was cancelled and relaunched with a new creative team due to the aforementioned ''Secret Wars'' reboot.
* Kieron Gillen's ''ComicBook/UncannyXMen2012'' had Mr. Sinister as the first villain, and he clearly had more plans in store. In the aftermath of ''ComicBook/AvengersVsXMen'', Sinister revealed that he'd been posing as the X-Men's PR expert from even before Gillen's run, and he challenged Scott to stop him once Scott got out of prison -- In fact, it's implied stopping Sinister is partly why Scott decided to break out of prison. None of this is followed up on, and the next time Sinister showed up proper, he had a completely new plan involving the terrigen mists.
* The 2003-2004 ''Comicbook/{{Venom}}'' series ended on a {{Cliffhanger}} where Venom mutated into a larger, even more monstrous form after absorbing the clone Symbiote that had bonded with Patricia. Worse still, he was shown preparing to fulfill the clone's mission to KillAllHumans at the behest of its alien masters. The next time Venom appeared, he'd returned to his classic form without any explanation, and while the clone later did resurface as Mania's Symbiote, the alien genocide plot was never resolved.
* Mike Costa's ''Venom'' run had the titular symbiote produce yet another spawn, and Eddie Brock agreed to work for Alchemax on the condition that they care for it. Costa's run was cut short by ''ComicBook/DonnyCatesVenom'', which featured a destitute Eddie Brock who makes no mention of the newborn symbiote. Eventually, a weekly series called ''Venom: First Host'' was released that allowed Costa to wrap up his story, and the newborn symbiote, dubbed the Sleeper symbiote, was PutOnABus.
* ''Comicbook/XMen'' has had multiple versions of them: the Baby version of Age of Apocalypse, how Comicbook/{{Psylocke}} and ComicBook/JeanGrey switched powers, evil Nurse Annie being sold off into bondage to Elias Bogan by her evil son, Sebastian Shaw being courted by Comicbook/{{Apocalypse}}, ComicBook/{{Magneto}} joining forces with the Neo, new character Sketch being set up to join the X-Men but then falling off the face of the planet as soon as Creator/ChrisClaremont left, Comicbook/KittyPryde supposedly having some sort of connection to the Neo, the mystery mutant that was present outside the Sentinel base in Uncanny X-Men #57-59, etc. One of the most infamous examples was the "Externals" plotline from Creator/RobLiefeld's ''Comicbook/XForce''. This secretive bloodline of mutants, all possessing immortality in addition to their mutant power, were built up to be the next big thing, with two former {{Big Bad}}s revealed to be members of the group, as was a member of the team, whom the others seemed to have various vaguely-defined "plans" for. However, Liefeld left the book before he could tie up all the plot threads, and the next creative team was quick to sweep everything about this story under the rug, with one of the three established characters in the group killing all the new ones and the other two revealed to not actually be Externals anyway. This happened so suddenly that many fans pointed out the fact that the story was essentially ''Franchise/{{Highlander}}'' with the SerialNumbersFiledOff and suspected Marvel canned the story to avoid litigation, though WordOfGod assures us this was not the case. There was also a subplot during Joe Kelly's run that hinted Jean might end up transforming into the Phoenix again. Kelly left the book before this could happen, though Creator/GrantMorrison ended up bringing back Jean's Phoenix abilities in his own run. There was also a plotline, dating back to the early nineties, where Bishop referred to Jubilee as "the last X-man", but that plot line has never resurfaced again.

* Jonathan Hickman's ''Fantastic Four'' run ended with the adult Valeria Richards gaining access to the space between universes that the multiversal Council of Reeds used as their base of operations. It was apparently her plan all along to gain access to this space, and she states that now she can build, an ominous reference to Doctor Doom's previous failed attempt at godhood. While Hickman's ''Fantastic Four'' run led into his ''Avengers'' run in a big way and the multiverse is collapsing within that story, nowhere does adult Valeria show up again.
* The end of the ''Jean Grey'' series had the younger Jean confronted by her older, modern day self, who said she wanted to talk. This isn't followed up on: young Jean goes back to ''X-Men: Blue'' while older Jean goes to ''X-Men: Red'', and the two barely interacted afterwards before the younger Jean was sent back to her own time.

* ''Franchise/TheAvengers''
** At the end of ''The Avengers'' #16, the departing Comicbook/IronMan told the new Avengers that they should track down Comicbook/TheIncredibleHulk and convince him to rejoin the team, as they currently lacked the raw strength of the original lineup[[note]]As Iron Man, [[Comicbook/TheMightyThor Thor]], and [[Comicbook/AntMan Giant-Man]] all took a collective leave of absence.[[/note]]. Despite the end of the issue promising "The Search for the Hulk!" the following month, issue #17 instead dealt with the Avengers facing the Comicbook/FantasticFour villain Mole Man, with the Hulk subplot essentially being abandoned within the first few pages.
** Near the end of Roger Stern's run, minor ''Comicbook/AlphaFlight'' character Dan Smallwood saw the Avengers on TV, and was shocked to learn his childhood sweetheart Marrina was now a member of the team. According to Stern, this was going to lead to Dan heading to New York and ending up in a LoveTriangle with Marrina and [[Comicbook/SubMariner Namor]]. Unfortunately, Stern was removed from the book by ExecutiveMeddling, and Creator/WaltSimonson ended up killing off Marrina in his very first arc.
** Creator/KurtBusiek's ''Avengers'' run had the team face a powerful villain named Bloodwraith. They were unable to best him, but ComicBook/ScarletWitch managed to bind him to the ruins of Slorenia, making it impossible for him to leave the country's borders. It was mentioned a few issues later that ComicBook/{{SHIELD}} was still monitoring Slorenia to make sure Bloodwraith didn't try anything funny, but Busiek ended up leaving the title before he could revisit that plot thread. The next time Slorenia appeared, absolutely no mention was made of Bloodwraith or where he'd disappeared to.
** Creator/GeoffJohns' first ''Avengers'' arc introduced a new Scorpio. Though his plan was thwarted, the ending showed that he had escaped with the Zodiac key, and that he was actually part of a new incarnation of the Zodiac group. Zodiac's mysterious leader mentioned that the next time, the group would attack as one to ensure the Avengers could not stop them. Unfortunately, there never was a "next time," since Johns left the book before he could continue that subplot. The new Scorpio and Zodiac never appeared again.
** Creator/BrianMichaelBendis hinted at a romance between [[Comicbook/{{Hawkeye}} Clint Barton]] and Echo in ''Comicbook/NewAvengers'', even having the two share a passionate kiss. This was completely dropped once Clint's ex-wife Comicbook/{{Mockingbird}} returned "from the dead" (it's complicated) at the close of ''Comicbook/SecretInvasion''.
** The official tie-in comic for ''ComicBook/TheAvengersEarthsMightiestHeroes'' had a story with the ComicBook/ScarletWitch and ComicBook/{{Quicksilver}}, which heavily implied that the two teens would be joining ComicBook/TheAvengers at a later date. Thanks to the cancellation of both the show and the comic, this never occurred.
* During a crossover between the ''Comicbook/AvengersAcademy'' and ''Young Allies'', it was hinted that Reptil and Spider-Girl harbored an attraction for one another, and were going to hook up. The problem is, ''Young Allies'' got cancelled after just six issues, so their relationship was nixed with a single HandWave line.

* ''ComicBook/CaptainAmerica'':
** Steve Rogers dies in Dan Jurgens' ''Captain America'' vol. 3 #50, which would have been addressed by a follow up mini-series by John Ney Rieber.
** Mark Gruenwald's final ''Captain America'' arc had Steve slowly dying, which led to him training a pair of young heroes named Jack Flag and Free Spirit to take over for him. Creator/MarkWaid then took over the book and promptly cured Steve, allowing him to get back into the action. The subplot about Cap's new proteges was dropped entirely, and Jack Flag wouldn't be seen again for roughly a decade, while Free Spirit wouldn't appear again until ''twenty years later''.
** ''Captain America and ComicBook/TheFalcon'' ended with Cap finding Falcon's costume fluttering in the wind, with it left ambiguous as to whether or not Falcon was dead. This was going to be resolved in a solo ''Falcon'' book by Creator/{{Christopher Priest|Comics}}, but the series never materialized, as Priest didn't want to be typecast as only writing black heroes.
** In the 70s, a crossover between ''ComicBook/CaptainAmerica'' and the ''Comicbook/XMen'' implied that Comicbook/TheFalcon might be a mutant. This was dropped until a decade later, when the solo ''Falcon'' series confirmed this theory by having a Sentinel identify the hero as a mutant. This was ignored until 2001, when Creator/KurtBusiek addressed the inconsistency in an issue of ''ComicBook/TheAvengers'', where it was established that Falcon was ''not'' a mutant, and that the Sentinel had simply been malfunctioning.
** When Steve Rogers returned after his supposed death in Ed Brubaker's run, Bucky -- who had been acting as Captain America to honour Steve -- insisted on giving the Captain America mantle back, even though Steve didn't want it. Steve insists that Bucky keep the title, and justifies it by saying that Bucky has moved beyond using the role to honour him. He later confides in a sleeping Sharon Carter that he'd had a vision of a possible future, and in this future Bucky, as the Winter Soldier and not Captain America, dies after being impaled on debris. Also seen are numerous large tentacled silhouettes and someone wielding Thor's hammer, Mjolnir. The ''ComicBook/FearItself'' crossover, where numerous Mjolnir-like weapons fall from the sky ''and'' Bucky ''was'' seemingly "killed" (but as Captain America), ''could'' be the follow-up, but it doesn't quite line up. The tentacle things never appeared and besides the event being Thor-related, there aren't many similarities. The visual of giant tentacled robots would be used years later in ''ComicBook/SecretEmpire'' (and a CBR article theorised that this could be a case of ArcWelding), but that's it.
** Near the end of Rick Remender's first run, [[Comicbook/{{Agent 13}} Sharon Carter]] returned after she was previously thought to have died in Arnim Zola's Dimension Z. She immediately accused Zola's daughter Jet (who had betrayed her father and sided with the heroes) of being a [[TheMole Mole]], and demanded that the girl be gagged so that she couldn't even defend herself against the accusations. Offended by the claim, as well as the heroes' willingness to believe it, Jet abandoned them and returned to her father's side. The way the situation played out made it seem like Zola might have been behind Sharon's mysterious return and actions, and that her accusations may have been an attempt to frame Jet to get her to turn against the heroes. However, this has never been addressed since then, and Jet ended up in ComicBookLimbo after Remender left the book.
** In ''All-New Captain America'', Comicbook/MistyKnight dropped the bombshell revelation that government organizations like Comicbook/{{SHIELD}} and various superhero teams like the Avengers, X-Men and [[Comicbook/TheInhumans Inhumans]] had been infiltrated by Comicbook/BaronZemo's new Comicbook/{{HYDRA}}. Again, Rememnder left the title before this could be further explored. While the later [[Comicbook/NickSpencersCaptainAmerica Nick Spencer run]] opened with Sam and Misty taking care of the last HYDRA moles within S.H.I.E.L.D., the thread about HYDRA having plants in the superhero community was largely ignored.

* ComicBook/UltimateMarvel
** During the ''Comicbook/{{Ultimatum}}'' crossover, Comicbook/TheWasp was [[DroppedABridgeOnHim killed after being eaten off-screen by the Blob]]. Before pulling a HeroicSacrifice, [[Comicbook/AntMan Yellowjacket]] was seen telling Comicbook/IronMan to take the Wasp's body into his lab and activate something known as "The Jocasta Project", hinting that her life might somehow be saved (since in the mainstream comics, Jocasta was an android with the Wasp's brain patterns). This was never mentioned again. In the same event, Comicbook/DoctorStrange was slain by Dormammu. Upon Stephen's death, a mysterious figure appeared in front of his corpse and teleported away with it. Like the business with the Wasp/Jocasta, this was never addressed or even mentioned again.
*** ''Ultimatum'' caused a lot of these. In ''Comicbook/UltimateXMen'', it had been revealed that Comicbook/EmmaFrost (who was thought to be a hero and ally to the X-Men) was actually a [[TheMole Mole]] working for the Hellfire Club. Emma was killed in ''Ultimatum'' (''offscreen'' no less) before this subplot could be continued.
*** In an ''[[Comicbook/UltimateXMen Ultimate Comics: X-Men]]'' arc following ''Ultimatum'', it was revealed that Havok was still alive and in a mental institution. He was released by Nathaniel Essex and introduced to Layla Miller, with the implication that there were plans for the boy. This plot point was never resolved, as the book ended up changing writers who never followed up on any of this.
*** Connected to this was a thread of several characters seeing "ghosts" of loved ones telling them to follow plans that made everything worse for everyone, much like Havok, with the implication that Apocalypse was the one behind it all, and that he was looking for a rematch with The Phoenix (after his last appearance had him be [[CurbStompBattle Curb-stomped]] by it), along with William Stryker Junior's mind being uploaded to all the Sentinels. Then Nick Spencer left, and the incoming Brian Wood didn't even pay lip-service to any of this.
** Well before the ''Ultimatum'' stuff, ''Ultimate X-Men'' #67 had Comicbook/{{Sabretooth}} drop the bombshell that he was Wolverine's son. Nothing ever came of this development, and when the two faced each other again in issue #89, Logan rather dismissively stated that there was no way that could be true.
** Comicbook/{{Mary Jane|Watson}} supposedly had the OZ formula purged from her body at the end of the "Clone Saga" arc in ''Comicbook/UltimateSpiderMan'', but there were still scattered hints that some of it remained. She briefly grew claws at one point during a tense argument between Peter and Comicbook/KittyPryde, and was shown having nightmares where she transformed back into the Demogoblin and killed Peter. This whole subplot was quietly dropped after a while.
** ''ComicBook/UltimateWolverine'': At the end of the series, Jimmy gets a Wolverine suit based on the one worn by Logan in the mainstream Marvel Universe. Despite promotional materials showing Jimmy in the costume, he never ended up actually wearing it.

''Comicbook/UncannyAvengers'':