Read This Before You See Dark Phoenix

The Dark Phoenix Saga, as it's come to be known through years of reprints and adaptations, is perhaps the most famous and widely referenced storyline in the history of X-Men comics, though its various adaptations have often taken a very loose approach to translating it to the screen. The setup for the story began in Uncanny X-Men #101 in 1976 with the X-Men embarking on a mission to space, during which Jean Grey encounters what seems to be a deadly solar flare. In that moment, instead of dying, she reaches the full potential of her Omega-level mutant powers. These powers are so great that they even allow her to briefly transcend having a body at all.

Jean later returns to her body, though when she reunites with the X-Men she has a new look, a greatly enhanced set of powers, and the name "Phoenix." For a while this was somewhat of a status quo in the X-Men comics, as Phoenix seemed to be able to hold back her own darker urges and maintain a power level that allowed her to remain a valuable ally to the X-Men. That would not last.

Though the X-Men are able to bring Jean's original personality to the forefront once again, there must be consequences for Phoenix's destruction. The Shi'ar empress Lilandra orders her Imperial Guard — a group of the best fighters in the galaxy — to abduct the X-Men and put Phoenix to death. Charles Xavier instead challenges the Shi'ar to a trial by combat: the X-Men versus the Imperial Guard, with the fate of the Phoenix at stake.

A lengthy battle ensues on the Blue Area of the Moon, but the Imperial Guard eventually defeat the X-Men. In the chaos, Jean struggles to keep control as the Dark Phoenix fights to overwhelm her body once again. Before this can happen, she uses a piece of alien machinery to kill herself after professing her love for Cyclops.

Jean Grey has come back from the dead more than once since this saga ended, but its impact remains clear among X-Men fans and within X-Men continuity. Jean Grey's struggle to retain her humanity even while tempted by the godlike powers within her remains one of the most emotionally satisfying and gripping X-Men stories, and now a major adaptation of it is finally coming to the big screen.

Jean will be the driving force of Dark Phoenix, but she's far from the only major character left over from Apocalypse to think about. The team at the X-Mansion now includes a reformed Ororo Munroe, a.k.a. Storm, as well as the speedster mutant Quicksilver and the teleporter Nightcrawler. Based on what we can glean from the trailers, this team seems to be in relatively stable shape as the film begins, with Xavier and senior members Mystique and Beast leading the way for the younger crew.

There's another mutant element at work in the wake of Apocalypse, though, and that's Magneto. Erik Lehnsherr allowed himself to be drawn in by En Sabah Nur's power, thinking he could use it as a means to make the world anew for mutantkind, but he was ultimately repulsed by the destruction, and helped the X-Men to defeat him. Now, after helping to rebuild, he's started his own little mutant community.

There are bigger questions hanging over all of this, of course, beyond the allegiances of individual mutant characters. What's changed about the world since Apocalypse? Who is still feeling the trauma of it? How will they bring those emotions to this new conflict? We'll have to watch the film to know for sure.

The character of Mystique — the shapeshifting mutant antihero who's sided with both Magneto and Xavier over the years — has been a part of X-Men franchise lore since the beginning. In the first film trilogy, she was played by Rebecca Romijn, and was firmly on the side of Magneto. X-Men: First Class took the character in a different direction, and drafted Jennifer Lawrence to play her.

Instead of beginning as a villain, Mystique was established as a young woman who grew up with Charles Xavier as his adoptive sister. Through First Class, Days of Future Past, and Apocalypse, her loyalties have shifted, but by the end of Apocalypse she was back on Xavier's side, helping to train young recruits like Cyclops and Jean Grey. Now, with Dark Phoenix, it's her time to go. Mystique's death in the film was revealed in the trailers, as a way of making it clear that Phoenix means business.

"Well, the thought process behind that was to primarily show that this is a movie that is unlike other X-Men movies," writer/director Simon Kinberg said. "It's a movie where shocking things happen, where intense, dramatic things happen," he said. "People don't just fall off buildings and dust themselves off and walk away. There's a reality to this movie and a consequence to this movie. Even more than that, it was to show that Jean/Dark Phoenix is genuinely a threat to everyone, including the X-Men."

Last year, as its release date began to shift around, word began swirling that Dark Phoenix might be facing as many as three months of reshoots in Montreal. If that was true, it meant a major retooling for the film, and that could have pointed to studio disappointment with what Kinberg and company turned out.

In the end, that turned out to be a false claim. Dark Phoenix did undergo reshoots last summer in Montreal, but the real schedule turned out to be more like two-and-a-half weeks. Why? Well, Collider reported at the time that the reshoots were primarily geared toward strengthening the film's third act with additional shots and perhaps a couple of new scenes.

Though fans often hear the word "reshoots" and begin to fear the worst about upcoming blockbusters, a period of a couple of weeks to rework certain parts of the film late in production is actually a somewhat standard procedure for a great many major releases.

In the Dark Phoenix trailers, we've seen glimpses of Magneto and Jean spending time in what looks like a kind of jungle commune, with makeshift structures and sparse signs of civilization. According to Kinberg, this is an early version of Genosha, one of the most important locations in X-Men comics, and a key component to the history of Magneto in particular. Originally introduced as a kind of mutant apartheid state (it's off the southeast coast of Africa), the nation eventually became Magneto's domain, and in the film it will serve as a place where he can attempt to create a kind of promised land for mutantkind.

"Jean finds him there because what's happening to her is making her do destructive things, and she doesn't know why," Kinberg explained. "The only person she's known who has done destructive and lethal things in the past but came back from it is Magneto. She feels he alone can give her answers because he's lived both sides. He's lost control and killed and hurt people, some of whom he even loved, and yet he's also found a measure of peace and that's what she's searching for."

Dark Phoenix is an X-Men sequel, which means we generally know who most of the characters are already, and what their alignments and powers are. Even in a film like Apocalypse, which introduced several new mutant characters, we still had a pretty good idea of who and what they were, because we had the comic books to draw from. That's not the case with this film in one particular instance: the character played by Jessica Chastain.

We've known Chastain is a part of the film for quite some time now, but we still don't have an official name to give her character. We also don't have a one-to-one comparison to a character from the comics that we can draw from, and that's apparently by design. According to Kinberg, she's an "alien" character with many different inspirations.

"Her character is an alien. She comes from another planet. When you see the entity that enters Jean in space is not a solar flare — it's a cosmic force," he said. "For those that know the comic, they know what the force is. Chastain's character is drawn and has been seeking out that cosmic force, and it leads her to Earth and to Jean. It's a force she either wants to control or destroy."