In the opening scene, two young girls, Laine and Debbie, are absorbed in a game of Ouija in Laine's room. As Debbie explains how to manipulate the planchette to tap into the spirit world, they recite the incantation, "As friends we gathered, hearts are true; spirits near, we call to you." However, Laine's encounter with a spirit is abruptly halted when she sees her younger sister Sarah, prompting her to shoo her away.
Fast forward to present day, the adult Debbie, played by Shelley Hennig, is alone, grappling with her encounter with the Ouija board. In a moment of distress, she discards the board into the furnace. Following a phone call with her friend Laine, portrayed by Olivia Cooke, Debbie declines an invitation to hang out that evening, dismissing her feelings of unease regarding the board as mere overreactions. After Laine departs, Debbie's unsettling experiences culminate as she finds the Ouija board back on her bed, leading to a tragic end when she takes her own life by hanging.
The next day, Laine is with her boyfriend Trevor, played by Daren Kagasoff, at a diner before receiving a concerning text from her father. Returning home, she discovers her family gathered, somberly revealing the tragic news of Debbie's death. The wake proves too much for Laine, despite her attempts to compose herself as Debbie's boyfriend Pete, played by Douglas Smith, arrives with flowers. After a heartfelt moment shared with Debbie's mother, Laine agrees to house-sit for the grieving family.
While sorting through Debbie's belongings, Laine uncovers the Ouija board. Haunted by the lingering presence of her friend, she gathers Sarah, Trevor, Pete, and Isabelle, played by Bianca A. Santos, to experiment with the board. As they chant the mantra and place their hands on the planchette, they are shocked when it starts moving, seemingly channeling Debbie’s spirit. However, as the paranormal activity escalates, each friend experiences chilling encounters with a malevolent presence.
In a sinister twist, Laine and her friends learn the spirit haunting them is not Debbie but DZ, revealing disturbing visions and a warning: "Run. She's coming." Further horrors unfold as Isabelle suffers an inexplicable, fatal encounter with the spirit. This intensifies Trevor's anger towards Laine for instigating their game, prompting her to delve into the dark history surrounding Debbie's home, where she discovers a tragic tale involving a missing girl and her mother.
Her search leads to a chilling visit to a mental asylum, where she meets Paulina Zander. Paulina recounts the horror of her sister Doris's plight, outlining how their mother believed malevolent spirits were communicating through Doris, leading to a horrific act of sewing her mouth shut. Paulina implores Laine to find and free Doris's body, intensifying the narrative's stakes.
Laine’s harrowing discoveries culminate when she uncovers Doris's decaying corpse, taking a harrowing step to cut open the stitched mouth, unleashing Doris's spirit alongside that of her malevolent mother. Just as it appears that the nightmare might be over, the horror continues, with Pete falling victim to Doris's wrath.
In a frantic race against time, Laine's grandmother reveals that to banish the vengeful spirit, both the Ouija board and Doris's remains must be destroyed. Armed with this knowledge, Laine, Sarah, and Trevor confront the horror at Debbie's house, leading to a heart-pounding showdown as spirits clash, culminating in a desperate act of sacrifice to finally banish the darkness.
With what seems like a resolution, Laine and Sarah return home, only for a chilling moment to unfold as Laine discovers the planchette once more on her desk, hinting that the terror might not be finished after all.
