In 1967 Los Angeles, a widow named Alice Zander works as a spiritual medium conducting seances with the help of her two daughters, teenager Paulina "Lina" and the youngest, Doris. Alice incorporates a new prop into her act—a Ouija board—to bolster her readings and provide clients with a more convincing experience of contacting the dead. Despite her good intentions to support her family financially following the death of her husband, Alice's seance business is not as genuine as her clients believe. The family itself is skeptical about the existence of the supernatural but uses the act as a means to help people find closure.

This skepticism is challenged when, during a session with the Ouija board, Doris appears to genuinely connect with the spirit realm. After this event, Doris begins to demonstrate strange abilities, claiming to be able to communicate with their deceased father and other spirits. Initially, the family believes this new ability could be a gift and could lead to real contact with the other side. However, as Doris's behavior becomes increasingly disturbing and unexplainable events occur within their home, Alice and Lina start to suspect that the spirits with whom Doris is communicating might have more malevolent intentions. Concern builds as they grapple with the unexpected consequences of using the Ouija board, leading them to uncover dark secrets and realize that they may have unwittingly invited dangerous entities into their lives.