It’s double the possession in “The Exorcist: Believer” when two teenage girls come back from the woods unknowingly bringing with them a demonic spirit that will forever change their lives.

When the novel by William Peter Blatty, The Exorcist, arrived on shelves in 1971, a spellbound populace devoured the story of shaken faith, family trauma and demonic possession. When director William Friedkin brought the story—from an original screenplay by Blatty—to the screen in December 1973, global audiences were treated to an unimaginable fear that shook them to their core.

Now, 50 years since the blockbuster’s theatrical launch, “The Exorcist: Believer” marks a new beginning that takes audiences into the darkest heart of inexplicable evil. “The original Exorcist film was groundbreaking for its time, and we wanted to honor the film with this continuation,” producer Jason Blum says.  While the 1973 film explored demonic possession from a predominantly Catholic perspective, The Exorcist: Believer incorporates multiple faiths in the fight to save two young girls.

“The film is dealing with the vulnerability of parenthood when you have a child with an unexplainable illness. How you approach a crisis like that is shaped by your own belief system: whether you’re a family that’s devout Baptist or a family that doesn’t believe in God, or a family that’s looking to the medical world, either with great hope or with great suspicion. The film engages in that conversation about science and spirituality,” shares director David Gordon Green.   

Much of the film’s research landed on the screen in various forms, and spiritual experts from every faith referenced in The Exorcist: Believer were hired to consult with the filmmakers and the actors. In the film, the mission to save the teenage girls includes four primary community faith leaders: Catholic priest Father Maddox (E.J. Bonilla), Victor’s friend Stuart, a Pentecostal preacher (Danny McCarthy), Doctor Beehibe, a root doctor (Okwui Okpokwasili) and Pastor Don Revans, a Baptist preacher (Raphael Sbarge).

As the production’s Spiritual Coordinator Carla Duren ensured the spiritual safety of the cast and crew—including their mental and emotional wellbeing.  Before production began, Olivia O’Neill’s mother brought her to a church in order to get a blessing (just to be safe). While there, she met the legendary Martin Sheen, who gave O’Neill his personal rosary for her protection during filming.

The rituals around exorcism and demonology are varied, fascinating and often mysterious.  According to Carla Duren, many of the ritualistic practices and spells seen and heard within the film are from actual exorcism rites and practices, including some of Doctor Beehibe’s practices, which are rooted in spiritual and healing methods that originated in various parts of Africa.  Additionally, according to project consultant Dr. David Bell, a professor at Georgia State University who specializes in psychology of religion, well-to-do religions, generally, do not have as many angry demons. But when life is rough, when minimum life requirements aren’t met in the lower socioeconomic status, there tends to be more demonology.

“The Exorcist: Believer” opens October 4 in cinemas nationwide from Universal Pictures International.