A 1980 X-Men story by Chris Claremont and John Byrne, taking place from Uncanny X-Men #129 to #137, and one of Marvel Comics' most iconic storylines.Fresh off a battle with Proteus, the X-Men are plunged into a battle with the mysterious Hellfire Club, while Phoenix, just back from a vacation in Greece and Scotland, finds herself psychically shifting in time to a Revolutionary War-era ancestor, who's engaged to a mysterious, roguishly handsome man named Jason Wyngarde.In between Jean's "timeslips," she helps the X-Men rescue new mutants Kitty Pryde and Dazzler from the Hellfire Club: White QueenEmma Frost, Black KingSebastian Shaw, White Bishop DonaldPierce, Black Rook HarryLeland, and probationary member Wyngarde. However, when the time comes for the final showdown with them, she mysteriously switches sides, fighting alongside Wyngarde and Hellfire against the team. As a result, the X-Men are soundly trounced, and Phoenix is named Hellfire's Black Queen.Thanks to a psychic rapport he forged with her before the attack, Cyclops manages to get through to Jean and reveal the truth to her: that Jason Wyngarde is really the X-Men's old enemy Mastermind operating under his real name, and that he's just making her believe she's time-shifting, the better to gain control of her through her Dark Side.Once Wyngarde's treachery is exposed, the X-Men get their second wind, defeating Hellfire and escaping into the night. But the damage to Jean's mind is done... even though she's free of Wyngarde's mind control, there's something inside her that's been broken.The corruption takes her over swiftly, and she transforms from Phoenix to Dark Phoenix a thousand feet over Central Park, destroying the X-Men's aircraft for about the dozenth time.note Technically, it wasn't even really their jet, but an Avengers Quinjet that then-Avenger Beast had "borrowed" in an attempt to come aid his old team, but Quinjets get blown up even more often than the Blackbird anyway. After a fight with those she loved, which can only be described as a Curb-Stomp Battle, Dark Phoenix leaves Earth altogether, triggering the Significance Sense of everyone from Doctor Strange to Spider-Man to the Silver Surfer. Zipping through the universe on a cosmic joyride, she finds herself getting hungry... and the nearest source of food is a star in the Shi'Ar Galaxy.The Dark Phoenix Saga is one of the most controversial X-Men stories of all time, more due to the RetCons and rewrites than the story itself, which was actually one of the most beloved tales in the franchise's history, and catapulted the already-well-liked Claremont/Byrne creative team to superstardom even as it sowed the seeds for what would eventually be their breakup.(It should be noted however that killing off Jean Grey wasn't their idea; editor Jim Shooter forced them to do it, feeling that allowing her to live after killing billions of people would not be fair. Claremont later admitted that it made for a better ending, and most fans agreed.note On the other hand...: another telling of the story is this — that the original intent of the Dark Phoenix Saga was for Jean to become a recurring villain on the order of Galactus or Doctor Doom, and it was the understanding of Shooter that she would escape to plague the X-Men and the universe later on. That, he was apparently perfectly fine with. When he learned how the ending was actually going to occur, with Jean being psychically lobotomized and released to the custody of the X-Men, Shooter deemed it a weak ending and morally unsatisfying and called Claremont out on it. (He later recalled it as being on the order of "taking the German Army away from Hitler after World War II and letting him go back to governing Germany.") Shooter first suggested that Jean!Phoenix be imprisoned permanently, but Caremont asserted that Cyclops would lead the X-Men on rescue mission after rescue mission to get her back. Shooter still demanded a just punishment for Phoenix. Out of frustration, Claremont suggested, tongue-in-cheek, that perhaps they should just kill her, believing that Shooter would not go along with it, as killing main characters permanently was just not done at that time. To his shock, Shooter endorsed the plan, leading to the Death of Dark Phoenix.)
Apocalypse How: Dark Phoenix eating the D'bari sun causes a Class X-2. It's suggested in issues of What If? that if she hadn't died, she would eventually have reached anything from a Class X-4 to a Class Z in time.
Ascended Extra: You notice the black-haired serving girl? The one taking the robe off Shaw while he gloats over the Hellfire Club's victory? She'll be important later.
To be specific, she turns out to be a spy for Professor Xavier (as well as something of a Canon Sue.)
Beware the Nice Ones: Even before her final Freak Out, Jean shows Emma Frost why it's not a good idea to make a mutant with cosmic powers mad at you. Mastermind learns a similar lesson, though by then Jean isn't so 'nice' anymore. See also Start of Darkness.
Years later, Claremont admitted that this made the story truly unique (for its time.)
Bullying a Dragon: The Imperial Guard fight the X-Men in a trial by combat, leaving Jean the last X-Man standing. When Cyclops is knocked out before her eyes, she snaps and becomes Phoenix again, taking them all out in the space of seconds.
The Bus Came Back: Beast and Angel, who had been serving on other teams, returned for the latter half of the story.
Chess Motifs: Hellfire ranks its members like this, with White Queen Emma Frost replaced by Black Queen Jean Grey after the former's apparent demise. Sebastian Shaw is the Black King, but the other members' ranks aren't revealed until later.
Phoenix's psychic duel against Emma Frost. Emma's able to hold out for a while, but it's quickly made clear that she has no chance of winning against Phoenix, who was only testing her to learn her strengths and weaknesses - it's over almost immediately once she really begins to attack.
The Hellfire Club's ambush of the X-Men, and in turn, the X-Men's retaliatory strike against Hellfire.
Of particular note is the No-Holds-Barred Beatdown Wolverine delivers to the entire Hellfire Club after having been smashed through several stories and into the sewers.
And finally, the X-Men's beatdown at the hands of the Imperial Guard. In fairness, the X-Men were badly outnumbered, but watching Colossus go down hard in a one-on-one fight with Gladiator is when it becomes clear they have no hope of victory.
The club itself was based on a Real Life 18th century secret club for decadent rich people.
Death Is Cheap: Originally meant to be explicitly averted by all involved — Jean Grey was to stay dead. Madelyne Pryor was intended to be just what she presented herself as — a normal human who just happened to have an uncanny resemblance to Jean. Unfortunately, it was decided about six years later that the original five X-Men should have their own book, and there had to be a way to bring Jean back. This led to the continuity trainwreck that was Inferno, and opened the door for the "Jean Grey Memorial Revolving Pearly Gates" jokes.
Dying As Herself: Jean chooses to commit suicide rather than become Dark Phoenix again.
Interrupted Cooldown Hug: Near the climax, Scott is talking Dark Phoenix down, trying to appeal to Jean's better nature with The Power of Love, with her face getting noticeably less inhuman and softer...until Professor Xavier mind-blasts her from behind, and she returns to full-fledged psychosis.
Light Is Not Good: The Phoenix Force is the embodiment of life, light, and fire, but also a rampaging, chaotic force with the potential to destroy entire planets if its power gets out of control.
Lost Aesop: The X-Men's usual "protect a world that fears and hates them" schtick was pretty much forgotten about for this story, as their antagonists were either mutants, former teammates, or aliens. However, the Aesop of the story itself, that power corrupts, was firmly held onto.
Mundane Utility: Phoenix uses her Reality-Warping powers for simple things like changing her costume into civvies or creating a picnic spread. Briefly, Cyclops wonders why this bothers him. "Why shouldn't Jean use her powers to make her life easier?"
Myth Arc: Part of what makes this story so remarkable. It was the climax of a massive Myth Arc that Claremont had been building up to since issue #97 in 1975, when Professor X got his first look at the Shi'ar. Over the course of 41 issues (almost five years), Jean Grey died, was resurrected, took on an alien empire, saved the galaxy from imploding, turned to the dark side, took on an alien empire (again), and died.
Restraining Bolt: Xavier creates a series of mental "circuit breakers" to permanently suppress the power of Phoenix, returning Jean to her "Marvel Girl" stats. But when she sees Cyclops wounded in battle, the Bolt breaks.
Say My Name: As Jean dies, she and Scott call each other's names.
Start of Darkness: To stop a carload of mutant-hunters from running down Kitty Pryde, Phoenix erects a psychic brick wall in front of it, killing the occupants. When Cyclops goes What the Hell, Hero?, she basically slaps him down.
Phoenix: You didn't sense the girl's terror, nor the thoughts of the men chasing her. These... animals got no more than they deserved! Cyclops: Wow. I thought I'd seen Jean in every conceivable mood, but this is new.
Superman Stays out of Gotham: Subtly lampshaded, as Marvel heroes from all over the universe pick up on Dark Phoenix's manifestation, but the whole story happens too quickly for anyone to respond to it.
And just before that, the Beast deliberately invokes the trope. Hank was an Avenger at the time, and happened to be on monitor duty when the NYPD alert about the X-Men fighting at the Hellfire Club came through. Instead of alerting his current teammates, he took a Quinjet out by himself to come to his former team's aid.
Super-Powered Evil Side: The original intent of this story was that Dark Phoenix was Jean Grey, corrupted by her power and Wyngarde's machinations. The Phoenix was retconned as a Cosmic Being of its own who had replaced Jean (and forgot about it) so the real Jean could turn up alive later.
There Is No Kill Like Overkill: When the Dark Phoenix suddenly reemerges at the climax of the saga, Empress Lilandra desperately invokes Plan Omega: destroy the entire solar system and pray they can kill Dark Phoenix in the process. At that point, Xavier has no choice but to order his X-Men to kill Jean themselves to preempt this measure.
Took A Level In Bad Ass: Sure, the Imperial Guard was pretty tough when they first appeared. In that fight the X-Men were gradually losing, least until Corsair and his team dived in. But the second battle....OW! Cyclops was off on his strategy and this was before Wolverine was a Canon Sue. And more importantly Mastermind goes from being a guy who goes 'boo' with fake monsters to almost destroying the X-Men all by himself.
What Have I Done: When Jean is restored to herself for the final chapter, she's consumed with guilt at the atrocities Dark Phoenix has committed.