Our Biggest Questions Digging Into The Horror Lore Revealed in First The Exorcist: Believer Trailer

With a little more than two months to go before its release, The Exorcist: Believer finally dropped its first trailer, after a weekend that saw the footage make its debut ahead of Oppenheimer in theaters. The first Exorcist movie in nearly two decades, it promises a legacy sequel approach that brings back one of the original film's most important characters in a big way.

Now, thanks to a couple of key details, we think we know why that character is so important to the future of the story.

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But before we get too deep into the details, if you still haven't seen the trailer, check it out below:

As you've probably heard by now, Believer is set to bring back Ellen Burstyn as Chris MacNeil, who returns to the Exorcist series for the first time since the original 1973 film. An actress by trade, Chris' life was forever changed when her daughter Regan (Linda Blair, a consultant on the new movie but not, so far as we know, appearing in the film) was possessed by a demon. Now, as two more families face the same threat, she's back to try to help.

What Brings Back Chris MacNeil?

Ellen Burstyn as Chris MacNeil in The Exorcist: Believer (2023) Photo: The Exorcist: Believer | Official Trailer/Universal Pictures YouTube

But why is Chris back now? The trailer might hold the clues. This time around, the possessed are best friends Angela (Lidya Jewett) and Katherine (Olivia Marcum), two girls who head off into the woods one day and, three days later, come back changed. The trailer spends most of its time focused on their descent into full-blown possession, but then Chris MacNeil shows up, and things start to seem a little more familiar, particularly when Chris visits one of the girls and says "We've met before" to the demon.

That line, coupled with the demon's repeated taunts through the use of the word "Mother," suggests that Believer isn't just dealing with another demon, but specifically with Pazuzu, the entity that possessed Regan MacNeil back in 1973, and the same demon that Father Lankester Merrin (Max von Sydow) was dealing with prior to meeting Regan MacNeil. Merrin's own past history with the demon would suggest that Pazuzu is persistent and holds grudges, and we know thanks to sequels that it never fully went away, so it makes sense that it would be back now, ready to possess more young girls and, perhaps, get some revenge on Chris MacNeil since she's the only one around from that original possession story.

What Happened to Regan MacNeil?

Ellen Burstyn and Linda Blair in The Exorcist (1973) Photo: Screen Archives/Getty Images

Which of course begs another question: What happened to Regan? We get a couple of additional hints about the past 50 years for the MacNeil family in the trailer, including a shot of Chris on TV and the cover of a memoir she wrote about her experiences. We also get photos of Regan as a child, though of course we don't see the adult version of her. The book and the TV interview are reminiscent of the lore from The Exorcist TV series created by Jeremy Slater in 2016, which sketched out a world in which Regan went into hiding and changed her name, while Chris wrote a bestselling book and, for a time, paraded her teenage daughter around on television. It's possible that something similar but distinct happened here, and Regan is simply gone, resigned to a quiet life away from the terror after what happened to her all those years ago.

It's also possible, and this is just a theory at this point, that Regan is dead, either through some kind of rough life following her possession, or through repeat encounters with Pazuzu. Chris makes reference in the trailer to having more experience with possession than she'd like to admit, and while any experience with demons is probably too much for the average human, this could also suggest that her story didn't end where the movies left it, that she had to keep fighting on behalf of her family long after the credits rolled on previous installments. So it's possible this is more than a grudge match. It's possible this is a revenge story, and Chris MacNeil is at the center of it all.

However it all shakes out, we can't wait to learn more.

The Exorcist: Believer hits theaters Oct. 13.