Following the success of their Halloween trilogy, writer/director David Gordon Green and Blumhouse re-teamed to tackle another esteemed horror property: The Exorcist.

The Exorcist: Believer possesses home video with an audio commentary by David Gordon Green, co-writer Peter Sattler, special makeup FX designer Christopher Nelson, and executive producer Ryan Turek, among other extras.

Here are 15 things I learned from The Exorcist: Believer commentary…

1. The film’s opening soundscape is inspired by a meditation app.

The film’s opening logos are accompanied by droning sounds inspired by calming music on a meditation app that Green uses.

“I am a fan of the mid-afternoon meditation shutdown, and I listen to a little app that’s full of singing bells and chimes and little brain cleansers, so I thought nothing better for our brainwaves than to open our movie with some of the same.”

‘Brainwaves’ was also the code name adopted for the production.

2. Green aimed to ground and contemporize the story.

While the majority of production took place around Atlanta, the prologue is shot in the Dominican Republic, standing in for Haiti, with footage of a real Haitian priestess performing a blessing. Green notes:

“When you’re handed the keys to this Ferrari, that’s one of the first conversations you have: what makes an Exorcist movie within this franchise? There’s been so many exorcism movies and content, but one thing we thought was important was opening in an exotic locale, characters out of their comfort zone, opening the audience to a world beyond their traditional awareness.”

In addition to paying homage to the original film, Green aimed to contemporize the story after 50 years of imitators. “One of the things that’s tricky too, when you’re talking about bringing this franchise back after so many years, is there’s a desensitization that’s happened in a lot of the quote-unquote horror movie fanbase.”

It was important to him to keep the story grounded from a human perspective. “As much as it can dabble in the supernatural, we can’t turn it into — where I feel like so many movies in this subgenre of horror have gone — they turn into superhero movies, and it just feels like something that doesn’t feel touchable anymore.”

3. Victor was originally a machinist, resulting in a character’s hand getting mangled.

In the first draft of the script, Victor was a machinist and his wife was a photographer. “He had a blue collar job, his wife was the artist,” Green explains. “The character of Stuart, who in the ultimate version lives across the street, he was a buddy that he knew at work.”

It was later decided to make Victor the photographer to add depth to the character. With the change, a scene in which a hand gets mangled in machinery was cut.

4. Co-composer Amman Abbasi wrote temp music for Green’s Halloween trilogy.

While Green retained much of the crew from his Halloween trilogy, he didn’t have John Carpenter, Cody Carpenter, and Daniel Davies compose the score for The Exorcist: Believer. Instead, he brought in David Wingo, who has worked with Green since his film school projects, and Amman Abbasi, Green’s former assistant.

“On the Halloween scores, [Amman] would do some temp music for us while we were waiting for the cut to get in shape to show Carpenter, because I would always be scared shitless to show it to John. For test screenings and whatnot, and for our own involvement and exploration, we would have Abbasi do these temp scores, and I just really was blown away by what he could do. The combination of David/Abbasi really bringing atmosphere and some experimental qualities to the music.”

5. Real police officers and doctors were hired to appear in the film.

No stranger to casting non-actors in smaller roles, Green hired police officers and doctors to portray their respective professions.

“For the most part … police officers play police officers, doctors play doctors. It’s the type of dialogue that’s hard to write, so you’ve got to bring in people that would say what they say and you kind of let them loose.”

The production also employed spiritual, police, and medical advisors to ensure accuracy. “Certainly for any religious authority that we needed to have, we’d bring in consultants,” Green says.

6. William Peter Blatty’s widow consulted with Green.

As part of the research which ultimately led to the girls using a paper “cootie catcher” to summon the demon, Green spoke to Julie Witbrodt, the widow of The Exorcist author William Peter Blatty.

He explains, “We’re thinking about research that Pete and I had done about all the various ways that in some interpretations could be a pagan communication, fortune telling. In the original film, it’s a Ouija board. We didn’t want to retread that game. How do you deal with these types of childish ceremonies?”

Witbrodt concurred with their findings. As Sattler relays, “She really stressed that, ‘Oh, no, these things come through strange things, like stuff that seems very harmless to us.’”

Green adds, “Some people even say through yoga or through these other places that you make yourself spiritually vulnerable, and that’s where an entity can find access to you. And I find that all really fascinating, because everyone has their spiritual perspective, and then once you have that perspective, the ceremonies and the rituals often follow.”

7. Jacob’s Ladder was an inspiration on the film.

Sattler says that he and Green “would watch other horror movies to find out things that we shouldn’t try to repeat, but then we would watch different movies from different genres, of dramas or foreign films, to find stuff that we wanted to bring in to this texture.”

As Turek describes, Green would show “curated films that are tangentially connected to what we’re trying to achieve” to the crew. Jacob’s Ladder, Eternal Sunshine of the Spotless Mind, and Lorenzo’s Oil are among the titles they screened and discussed.

Green also cites Jacob’s Ladder as an inspiration on the scene shown from Katherine’s possessed perspective.

8. A scene with feces was reshot after test audiences laughed at it.

The sequence in which Victor discovers Angela has wet the bed and puts her in the bathtub before she attacks him was the result of a reshoot following test screenings.

Green divulges, “The original sequence was that he gets into the room and he smells shit, like something foul has happened. He doesn’t find anything in the sheets, takes her, and then there’s shit on the wall that she’s spelled ‘mother’ in.”

Test audiences laughed at the sight of feces, which was not the response Green wanted from the moment. “It’s the perfect example of something that to me was disgusting and unnerving, but you show it to a handful of people, they think that just seeing shit everywhere is undeniably funny.”

Sattler credits Green’s openness to adapt and improvise. “I think it’s for the best though. It’s kind of a subtler, a little more of a grounded, less of a popcorn-horror moment.”

9. Chris MacNeil’s journey echoes Ellen Burstyn’s real life.

Ellen Burstyn returning as Chris MacNeil into the film was “a very delicate balance,” according to Sattler. “She’s not the protagonist. This is Victor’s story, but she plays such an essential role in it.”

Green explains, “I had just read Ellen Burstyn’s autobiography [Lessons in Becoming Myself] and had been inspired by her life in the wake of the original film and the success of The Exorcist, and then trying to parallel that in Chris’ journey in the wake of the events in Georgetown and how that opened her worldview to travel and gurus and priests and priestess, and seeing how the journey of Chris could echo the real journey.”

Burstyn proved to be a valuable resource to the creative process, helping to further develop the character with Green. The character further developed after Green spoke with Burstyn. He transcribed their conversations, some of which ended up in the dialogue. “Just bringing her into the creative fold of it was amazing.”

Similarly, Chris’ relationship with Regan evolved. Green explains, “We evolved that so many times, particularly once befriending Linda Blair and talking to her about what she felt was a true story, the opportunity for that character and their relationship.”

10. A couch from The Exorcist appears in the film.

Burstyn still owns a couch from The Exorcist, so it was used as set dressing in MacNeil’s house — although its been reupholstered, and only its arm appears in the corner of a wide shot of the final film.

“When I first started talk to Ellen, she’s like, ‘I have the couch from the film that I got just to furnish my apartment after we wrapped, and you should put it in the movie.’ The only thing that remains in the shot is that arm of the couch, but it cost a lot to ship it from New York City,” Green laughs.

11. Christopher Nelson was skeptical about filling Dick Smith’s shoes.

Even after tackling Michael Myers in Green’s Halloween trilogy, Christopher Nelson was skeptical about filling the shoes of The Exorcist makeup artist Dick Smith, who Nelson considers his idol.

“At first I was skeptical of doing it, to be honest with you. For a moment, I was like, ‘I don’t know.’ Not because I wasn’t confident in my abilities, but how do you go up against that iconic — how do you do it? I think you just do it with honesty and as a fan.

He continues, “The idea was to keep it real and keep it organic, I think.” At its worst, the girls’ makeup application took two and a half hours to apply and thirty minutes to remove.

12. Three girls were possessed in an early draft of the script.

An early draft of the script featured a trio of girls becoming possessed with all three of their families getting involved in the exorcism.

“I remember when you called me and said, ‘I want to lose a girl,’ and I was just like ‘Oh my god, I don’t know what to do,’” Sattler recalls. “But it is, like many things in this film through this strange challenge, we discovered something so much better. Two girls is such a more perfectly balanced two-sided coin. It works so much better.”

“It proved to be that way, through finding of the ending of the film and the choice’s that’s made,” Turek adds.

Director of photography Michael Simmonds helped Green realize that two families was a better choice. “Think about three more people in every scene. The movie’s gonna be 30 minutes longer by the time you get a really fleshed out perspective. The coverage to get everybody’s reaction and involvement, and you’re all in a room. It’s a crowded, sweaty house in Atlanta,” he snickers.

In another draft, Victor became possessed.

13. The ending came through prayer.

Struggling to come up with a satisfactory conclusion even during production, Sattler turned to prayer. As he tells it:

“We were struggling. David was like ‘How do we end this film? We need something better. What do we do?’ We must have thought about a thousand ways to do it. This is an honest-to-God story. I sat down in my kitchen and I prayed. I swear to you. We were running out of time, and it was like, we’ve gotta do this right. I prayed for this ending.”

Divine intervention? The idea came to him that night, and he stayed up to write it before sending it to Green, who agreed it was the right ending.

14. There is a slight difference between the American and European cuts.

Father Maddox’s death is slightly different between the American and European versions of the film. “If you’re watching the American version of this movie, the neck doesn’t stop twisting. The European version, it stops twisting. There’s like six extra frames,” Green explains.

“It was a very last-minute change that I wanted to make, and we’d already sent it out to our European exhibitors,” he chuckles. “European, his head stops turning. I wanted the momentum of the continuation. I didn’t want it to stop.”

15. The big cameo was kept secret from most of the crew.

Linda Blair’s big cameo at the end of the film was kept secret. “I’d say 95% of the crew didn’t know what was happening,” Green recalls. “There was a bogus call sheet that went out, and very few people knew that when we said action Linda was going to enter.”

The actors’s first time reconnecting in many years was captured on camera in single, powerful take. Sattler calls the connection between the two of them “palpable,’ while Turek admits to hiding tears of joy.

“It was an extraordinary moment to be part of that, to take those two amazing actresses, Linda and Ellen, from a monumental Hollywood movie and be there for that reunion,” Green concludes. “It was pretty special.”

The Exorcist: Believer is available now on 4K Ultra HD, Blu-ray, DVD, and Digital.