When Ellen, the matriarch of the Graham family, passes away, her daughter's family begins to unravel cryptic and increasingly terrifying secrets about their ancestry. The more they discover, the more they find themselves trying to outrun the sinister fate they seem to have inherited.
Annie Graham, an artist who specializes in miniatures, lives with her husband, Steve, their 16-year-old son Peter, and their 13-year-old daughter Charlie. At the funeral of her secretive mother, Ellen, Annie delivers a eulogy explaining their fraught relationship. Shortly after, Steve is informed that Ellen’s grave has been desecrated, while Annie thinks she sees Ellen in her workshop. At a support group for those who have lost loved ones, Annie reveals that, growing up, the rest of her family suffered from mental illness that resulted in their deaths.
Annie forces Peter to take Charlie to a party with him. Unsupervised, Charlie eats cake containing nuts, which she is allergic to, and falls into anaphylactic shock. On the way to the hospital, Charlie partially climbs out of the window to get air. Peter swerves to avoid a dead animal and Charlie is decapitated by a telephone pole. The family grieves following Charlie’s funeral, heightening tensions between Annie and Peter. Peter is plagued by Charlie’s presence around the house.
Annie is befriended by a support group member, Joan. Annie tells her she used to sleepwalk, and recounts an incident in which she woke up in Peter’s bedroom to find herself, Peter, and Charlie covered in paint thinner with a lit match in her hand. Joan teaches Annie to perform a séance to communicate with Charlie.
In a nightmare, Annie reveals to Peter that she tried to abort him when she was pregnant. Awake, she convinces her family to attempt the séance, during which Charlie seemingly possesses her until Steve douses her with water. Annie suspects that Charlie’s spirit has become malevolent. She throws Charlie’s sketchbook into the fireplace, but her sleeve also begins to burn. She retrieves it and heads to Joan’s apartment for advice, but Joan has vanished…