Cassidy McCabe is having a bad day when her cat turns up missing and her client Dana undergoes a frightening flashback in which she witnessed a Satanic ritual. Knowing Dana has a psychiatric history, Cassidy is uncertain whether to take the suddenly recovered memory as reality or delusion. But when she tells the story to her partner in crime solving, investigative reporter Zach Moran, he recognizes the place Dana describes and insists on searching for evidence. As the evil that emerged deep in the forest preserve more than 20 years ago moves into the present, Cassidy begins to fear not only for her client's life but for Zach's and her own as well.