In the heart of Haiti, photographer Victor Fielding and his pregnant wife Sorenne, blessed by a local voodoo practitioner, embark on a blissful honeymoon, when disaster strikes in the form of a massive earthquake. This traumatic event leaves Sorenne gravely injured, forcing Victor to make an unimaginable decision: save his wife or their unborn child.
Fast forward thirteen years, and we find Victor, now bereft of faith after the loss of Sorenne, raising his daughter Angela alone in Georgia. One fateful day after school, Angela, along with her best friend Katherine West, sets off into the woods to conduct a séance, hoping to contact her late mother. The girls soon go missing, prompting a three-day manhunt that ultimately ends when they are discovered in a barn. Though they return home seemingly unscathed, it's clear that the ordeal has left them traumatized.
As the days pass, Angela's behavior takes a dark turn—she violently attacks Victor, and undergoes strange convulsions. Meanwhile, Katherine experiences an alarming outburst during a church service. Faced with the unsettling reality of their daughters’ conditions, Victor admits Angela to the hospital, where they're attended by their neighbor, Ann Brooks. As dread fills the air, Katherine’s mother, Miranda, speaks out, suggesting that the girls might have traversed to Hell and brought a demon back with them.
Concern for their daughters escalates when they experience further deterioration. Convinced of Angela's possession, Ann provides Victor with a memoir penned by Chris MacNeil, who faced a similar terrifying occurrence with her own daughter Regan in 1973. Chris has devoted her life to studying exorcisms globally, and although she hasn't seen Regan since the memoir's success distanced them, she is determined to help Victor. However, things take a harrowing turn when Chris attempts a deliverance ritual on Katherine, only to fall victim to the girl's violent actions.
Desperate, Victor, Miranda, Ann, and Katherine's father Tony seek help from the church for an exorcism. Chris recommends incorporating various cultural practices into their efforts. To this end, they enlist the help of Father Maddox, a local priest, Don Revans, a Baptist pastor, Stuart, a Pentecostal preacher, and Dr. Beehibe, a rootwork healer. As they prepare for a unified exorcism, the local Catholic diocese blocks Maddox’s involvement, claiming the children suffer from psychiatric issues.
During the exorcism, the girls are bound to chairs, with Ann wielding a crucifix inscribed with the Saint Benedict Medal to confront the demonic presence. In a chilling moment, the demon reveals a heart-wrenching truth—the choice Victor made thirteen years ago was not to save Angela, but Sorenne, who succumbed to her injuries. As tensions rise, the demon forces a cruel ultimatum: they must choose who will survive, leading to a fate-altering confrontation.
With their lives hanging in the balance, the atmosphere becomes unbearably charged. The demon brutally murders Maddox, but in a moment of renewal, Victor rediscovered his faith and prays for his daughter while attempting to bolster her spirit with Sorenne's scarf. As the demon's influence tightens, a select choice must be made. When Tony finally declares his choice, Angela flatlines.
In a shocking twist, Katherine finds herself in a different realm, calling out for her parents, as the demon claims her, revealing the true nature of its selection. With Katherines's fate sealed, Angela gasps awake as the police arrive, but not before Katherine's heartbreaking demise unfolds on the scene.
In the emotional aftermath, while Angela processes her traumatic return to school, Miranda and Tony grieve for their lost daughter, and Victor makes a pilgrimage to Sorenne's grave. In a poignant parallel, Chris finds reconciliation with Regan in a bittersweet hospital reunion, providing the only glimmer of hope amid the chaos and loss.
