Clyde and Stephanie Brenek, recently separated, are trying to manage their lives and the well-being of their two daughters, Emily and Hannah. During a weekend visit to a yard sale, Emily becomes fascinated by an antique wooden box inscribed with strange Hebrew letters. Upon bringing the box home, Emily begins to exhibit increasingly erratic and violent behavior, drawing the concern and confusion of Clyde and Stephanie. Initially dismissing the changes as a reaction to the divorce, they soon realize that something far more sinister is influencing their daughter.

As Emily's condition worsens, Clyde investigates the origin of the box and learns that it is a dybbuk box, a container designed to imprison an evil spirit according to Jewish folklore. Desperate for help, Clyde consults Jewish religious experts, who confirm the presence of a malevolent entity intent on consuming Emily. Faced with this terrifying revelation, Clyde and Stephanie must come together to save their daughter from the malevolent force that possesses her, leading them into a battle against an ancient evil that threatens to destroy their family.