A trailer for Star Wars: The Rise of Skywalker unveiled a dark side version of Rey - and she could actually be possessed by Palpatine. Star Wars: The Rise of Skywalker's writer and director J.J. Abrams is well known for his so-called "Mystery Box" approach to marketing. Under Abrams' watch, each trailer is carefully designed to raise more questions than answers, to stir up debate among fans, and to leave viewers eager to see the mysteries resolved when the film finally comes out.

At this stage, the trailers for Star Wars: The Rise of Skywalker have raised two major questions. The first trailer confirmed that Emperor Palpatine is set to return; it's unclear whether he's survived death or is in fact a Force spirit of some kind, and there have been few hints about his role. The second trailer ended with a haunting shot of a dark side version of Rey, wielding a crackling red double-bladed lightsaber. Was it a Force vision, akin to Luke's experience in the Dagobah cave in The Empire Strikes Back, or will Rey turn to the dark side?

Related: Star Wars: The Rise of Skywalker D23 Trailer Breakdown: 18 Story Reveals & Secrets

On the face of it, these are two separate mysteries. But they could be tied together - because dark side Rey could really be the first glimpse of Palpatine returning to the fold, and in the flesh.

How the Sith Can Survive Death

Star Wars canon has always been clear that Sith can somehow survive death - but not in the same "Force Ghost" sense as the Jedi. In order to become a Force Ghost, a light side adherent has to submit to the will of the Force, right down to accepting their death; dark siders are driven by an egotistical desire to impose their own will upon the Force, which means they're naturally unable to become Force Ghosts. Matt Stover's novelization of Star Wars: Episode III - Revenge of the Sith made this explicit. Stover worked closely with George Lucas himself on the script, and was given permission to amplify many of the scenes. As a result, he extended the conversation between Qui-Gon's Force Ghost and Master Yoda to include a longer discussion of immortality. "The ultimate goal of the Sith, yet they can never achieve it," Qui-Gon explained. "It comes only by the release of self, not the exaltation of self. It comes through compassion, not greed. Love is the answer to the darkness."

There is, however, one canon way that a Sith spirit can endure after death. A Sith can transfer their very essence into some physical relic, or can bind itself to the geographical place where they died and essentially "haunt" it. Star Wars: The Clone Wars season 6 included arcs in which Sith spirits were seen inhabiting a specific site, while Charles Soule's recent Darth Vader comic introduced Lord Momin, a Sith heretic whose spirit had inhabited a mask. This power is referred to as an "Essence Transfer", and it's important to note that Palpatine probably knew it; he'd possessed Lord Momin's mask for years before he loaned it to Darth Vader.

It's quite possible that Palpatine survived death by using the Essence Transfer ability. Indeed, that would explain why Lucasfilm has so far avoided showing any footage of the Emperor at all; the only image so far as is a Star Wars 9 poster released at D23, and the cartoonish artwork has made many suspect the Emperor lacks a physical form. As noted, J.J. Abrams is secretive, and his reluctance to show the Emperor may mean that he's holding this revelation back for later in the marketing campaign - if not for the film itself.

Related: Why Does Star Wars 9’s Emperor Palpatine Look Like A Cartoon?

Palpatine's Servants Dreamed Of His Being "Enfleshed" Again

The Cover of Aftermath: Empire's end featuring a crashing Star Destroyer

Lucasfilm dropped the first hints of Palpatine's eventual return back in 2017, in the novel Aftermath: Empire's End. Written by Chuck Wendig, this book explained the Empire's defeat at Jakku, and revealed that the last survivors fled to the Unknown Regions, where they presumably formed the First Order. It featured a Sith cultist called Yupe Tashu, who had served under Palpatine and was convinced his Master had somehow survived death. "Palpatine lives on," he insisted. Another aide - who didn't actually believe it, but was trying to placate Tashu - made a fascinating comment. "The mantle of the dark side is yours to wear, at least for a time," he told Tashu. "At least until we can find Palpatine and revivify him, bringing his soul back to flesh anew."

Back in 2017, readers assumed that Yupe Tashu was simply insane. Palpatine's impending return changes that, turning this into a fascinating and important clue. Tashu seemed to believe that Palpatine's spirit had been transferred to a relic or geographical place, and that his servants had to find him and bring a potential host to him. Charles Soule's Darth Vader run confirmed that a Sith spirit can possess anyone who comes into contact with the relic that it resides in; in that case, anyone who saw Lord Momin's mask was tempted to put it on, and doing so left them under the Emperor's thrall. That would fit with the idea of "bringing [the Emperor's] soul back to flesh anew."

Related: Star Wars Canon Already Explained How The Emperor Survived Return Of The Jedi

Rey Could Become Palpatine's Host

Dark Side Rey activates her lightsaber in The Rise Of Skywalker.

That naturally raises the question of just who Palpatine would consider to be a worthy host. The latest Star Wars trailer ended with a mysterious glimpse of a dark side version of Rey, wielding a crackling red double-bladed lightsaber. There was something strange about Rey in this shot; her body was held unnaturally straight, and her facial expression was fixed in a glare. All this seems particularly odd given that Star Wars: The Last Jedi ended with Rey seeming to commit to the Jedi and the light side of the Force. Perhaps the explanation is that Rey has been possessed by Palpatine. It's already been confirmed that Rey and Kylo Ren will both head to the wreckage of the Second Death Star, the place where the Emperor died. If his spirit is haunting that location, then he could possess her; if he has contained his essence within a relic, then Rey could stumble upon it.

A close look at that shot reveals that dark side Rey is wearing a mysterious ring with a black stone upon it. It's possible that is the relic the Emperor placed his spirit within, and he has compelled Rey to wear it, taking control of her body. Interestingly, the original working title for Star Wars: Episode IX was "Black Diamond", which may well hint that this dark stone is important somehow. If Rey has indeed been possessed by Palpatine, then ironically her salvation could be Kylo Ren. She and Kylo Ren possess an intimate Force bond, created by Snoke but still be there even after his death. That bond would mean Palpatine has chosen a host who can potentially draw upon the Force power of another being, and so resist his influence more than anyone else. The Emperor may well have made a big mistake if he does possess Rey in Star Wars: The Rise of Skywalker.

More: Star Wars 9 Theory: Dark Side Rey Is A Clone (& So Is The Original)

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