All those who were once Avengers, everywhere around the world, are suddenly attacked by Asgardian creatures, who vanish at the same time. Iron Man, Captain America, Giant Man and the Wasp meet at the mansion to discuss what's going on; Thor (whose wereabouts were still unknown) appears there as well, announcing a great crisis. All the former Avengers are summoned, and Thor explains that all living beings in Asgard have dissapeared, for reasons unknown. But Thor noticed a bigger problem: the giant sword of Ragnarok was missing, as well as the Norn Stones. The Avengers divide into four groups to search for the stones and the sword. It turns out to be a plot of Morgan Le Fey and Mordred, who manipulated the Avengers to send teams in order to capture the Scarlet Witch, and then be able to exploit her magic to be able to use the sword to reshape reality.
In the new reality, Morgan Le Fey is the absolute queen of a world in the middle ages. The Avengers are now the "Queen's Vengeance", their suits, powers and origins are redesigned for the middle ages, and they are brainwashed into being the Queen's servants. The Scarlet Witch is the exception: she is still herself, and she's kept chained in a cell. She begins to use her magic to summon help, and had some success: "Yeoman America" (Captain America) recovers his memory. He forces "Longbow" (Hawkeye) to remember, and they begin to try to make the others remember as well. But the spell is strong, and not all of them remember their real lives. After a big fight, the awakened Avengers (Captain America, Hawkeye, Thor, Photon, the Wasp, Quasar and Justice) escape to the forest. And the Scarlet Witch finally summons Wonder Man back from the dead, who liberates her.
The Avengers return to the castle, and another fight begins. The Scarlet Witch shows up as well, and begins a magic duel with Morgan Le Fay. But Le Fay is stronger... until Wonder Man shows up again. And, with her attention focused on the 2 threats, all the members of the "Queen's Vengeance" begin to recover their memories, and add their forces to Wanda's. She's finally defeated, and the world returns to normal.
But that does leave the question of what they're going to do with thirty-nine Avengers...
Heroes Return contains examples of:
- Absolute Cleavage: Morgan's outfit is a metal shirt that shows off a lot of her flesh.
- All There in the Manual: Avengers Annual 2001 would later explain why many of the changes caused by The Crossing were undone. The reason being that when Reality Warper Franklin Richards used his powers to save the Fantastic Four and the Avengers, he wasn't aware of the teenaged Tony Stark or mutated Wasp, so he restored Wasp to her classic self and, while nothing was done with it, resurrected the adult Tony and fused him with Teen Tony, resulting in the adult Tony also having his counterpart's memories, as well as (until Matt Fraction's Hawkeye run), restoring Hawkeye's hearing.
- Attack of the 50-Foot Whatever: In the final fight, Morgan uses her magic to make herself giant. Wonder Man responds in kind.
- Back from the Dead: Wonder Man, after dying in the opening issues of Force Works some years ago. And this time it's for real (well, not quite, but he's more alive than dead. It took a year before he comes all the way back to life).
- Big "NO!": At Morgan's defeat
- Blue Blood: Hawkeye points this as why trying to de-brainwash Iron Man first was not Cap's best choice - Tony is an Avenger, sure, but he's too much of a "man of the manor", comfortable living in a medieval fantasy world, for it to take effect.
- Bullying a Dragon: A pair of slightly drunk thieves try hitting on the brainwashed She-Hulk and Ms. Marvel.
- Complexity Addiction: Lampshaded. Mordred points out to Morgan that instead of tricking the Avengers into reuniting and bringing the Scarlet Witch to them, they could have just kidnapped the Scarlet Witch. "What good is victory without risk?" replies Morgan, explaining that she had to get the Avengers involved so she would have a Worthy Opponent to defeat.
- Continuity Nod: The third issue begins with Morgan angrily screaming about some of her past exploits, including the time she escaped a collapsing Atlantis (in Fantastic Four: Atlantis Rising).
- Covert Pervert: Morgan's assigned jailer enjoys watching Wanda squirm as she's chained up in prison.
- In issue 1, Wanda disperses a Morgan-made tornado, and she notes that it felt like the energy she used to disperse it was... alive somehow. At the end of the next issue, she manages to summon Wonder Man.
- In Morgan's world, Ms. Marvel is introduced eagerly looking for a strong drink. The first year of Busiek's run on Avengers would follow up with her becoming an alcoholic in response to losing her Binary powers.
- The Friend Nobody Likes: A lot of the secondary Avengers spend issue 1 grousing about D-Man. Not because of any personality issues, just... he smells really, really bad.
- Genre Savvy: In order to get into Morgan's castle, Cap suggests disguising the team as monks. Hawkeye points out this never actually works. Sure enough, as in the movies, they're revealed the minute they're through the gate.
- A Glitch in the Matrix: The second issue begins with one, as Donnar (Thor) realizes that many things are not right. Morded suspects the brainwashing isn't working on Thor because he was alive in the middle ages. Actually, it's Wanda fighting back against the spell.
- He's Back!: The Avengers are back in business.
- "I Know You're in There Somewhere" Fight: Cap doesn't stop doing this even when thirty-odd of his brainwashed comrades in arms are trying to beat him to a pulp.
- Incoming Ham: Thor returns to Avengers Mansion with the appropriate level of Asgardian ham, ranting about the impending destruction of Midgard. Wasp actually has to take a second to remember that Midgard means "Earth".
- Jerkass Ball: Hulk responds to a call for arms from the Avengers by telling them if they do it again, he'll come and smash them.
- Kick the Dog: Morgan kills Mordred for pointing out everything's gone to crap.
- Living Macguffin: Morgan needs Wanda to keep her fantasy world going. No Wanda, no fantasy.
- Loads and Loads of Characters: Pretty much everyone who'd been an Avenger gets called up, or at least makes a cameo. Oh, and Justice and Firestar, who tag along with Rage and get dragged into everything.
- Magitek: How the Iron Knight armor works in Morgan's fantasy world.
- Mythology Gag: At the end of the story the team is back in business, with all its former members. Citing the Angel, the Beast asks "What are we going to do with 39 Avengers?". That's a similar ending to Giant Size X-Men, when the old team (Cyclops, Marvel Girl, Iceman, Angel, Havok and Polaris) was rescued by a new team organized by Xavier (Wolverine, Banshee, Colossus, Storm, Nightcrawler, Sunfire and Thunderbird). (Incidentally, Beast only made a cameo in that story because he was with the Avengers at the time.)
- Naïve Newcomer: Justice (of the New Warriors, he shouldn't even be there, he accompained Rage because he was with him when attacked), though he's not new to heroing by any means, just nervous because he's around the Avengers. Thor explains the Asgardian attacks, and that someone's stolen the Twilight Sword and the Norn Stones... and Justice points out that it must be a trap. Everybody looks at him with disdain. "Oh, of course it's a trap. You already knew it. I'm sorry. Can I die now, please?"
- Not Me This Time: With the Asgardian creatures, the mystery over the fate of the Asgardians and the magic involved, many may have believed that the villain would turn out to be Loki (the villain of the first issue of the Avengers). The characters suspect it a pair of times, but he's not; in fact, he's among those missing.
- Oh, No... Not Again!:Hawkeye: Not another alternative reality! Not again! Oh, well - at least this time I'm not dressed like a brown Plantman...
- Only Mostly Dead: How Simon describes his condition after his death back in Force Works, unable to restore himself.
- The Pig-Pen: D-Man has been living in the sewers (in a city, not just homeless) for some time now, and as a result, he smells bad. Really bad. At the big team meeting, he's sitting in the middle of the chair, and everyone else is giving him a wide berth.
- Refusal of the Call: Reed Richards, Sue Storm and Ben Grimm had all been Avengers at some point, but were busy with things as the Fantastic Four. And Hulk... he had been attacked by Trolls, and wasn't in the mood for meeting others, especially the Avengers. Spider-Man (a reserve member at the time) appears for the meeting, but asks to leave because he had problems in his own titles to deal with. Moon Knight also got the call, but he's in I Work Alone mode, and doesn't get involved.
- Rousing Speech: Cap gives one to try and break the Avengers out of Morgan's brainwashing. It works on one or two of them (Wasp, Monica Rambeau, Quasar, Justice), but just as it's about to break everyone else free, Namor's historically crappy temper kicks in, and he tries decking Cap.
- Something We Forgot: The fate of the Asgardians isn't investigated, the Sword and the Norn stones were more important at the moment. Thor would investigate that other topic in his relaunched comic book.
- Spot of Tea: The first thing we see the Avengers's leaders doing? Having some nice Jarvis-made tea as they discuss the situation.
- Stupid Evil: Morgan decides to brainwash Earth's Mightiest Heroes and keep them as her royal guard, so when the brainwashing fails, she's got an army of pissed-off heroes right next to her. She also repeatedly tells Mordred to shut up whenever he points out the flaws in her plan.
- Surprisingly Realistic Outcome: Morgan Le Fay rewrites reality so she's in charge, and through the arc Mordred keeps reminding her this means she actually has to, y'know, rule. Meaning all the boring stuff like administration and such.
- Talking Is a Free Action:
- At the very beginning, Luna sees something approaching the restaurant she, her parents and Wanda are dining in, and screams out a warning to all four, before whatever it is can smash dramatically through the window. Said threat manage to belt out a small monologue as they smash through a window.
- Pietro later gets his own example, when he beats Morded, but his super-speed lets him get away with that (though as to how the others can hear him say it... *shrug*).
- Team Hand-Stack: When the original Avengers agree to fight together with Thor.
- The Power of Love: What allows the Scarlet Witch to bring Wonder Man back from the dead.
- Undying Loyalty: Cap's critera for who he tries to de-brainwash is those who have this for the Avengers. He starts with Hawkeye.
- Universal-Adaptor Cast: The big point of the adventure, besides the return itself, was to turn the Avengers into medieval characters.
- Wedding Smashers: King T'Challa of Wakanda is at a friend's wedding when Asgardian creatures see fit to attack him.
- You Have Failed Me: The Scarlet Witch escapes, rescued by Wonder Man, and her jailer was not present. As a result, he has no idea what happened. Morgana turns his head into a pulp, as he is of no use to her.