In a quiet corner of the United States, Mackenzie "Mack" Phillips leads an apparently normal life, but everything changes after a heartbreaking tragedy: the disappearance of his youngest daughter, who is kidnapped during a family trip. Distress and guilt consume him, leading him to question his beliefs about faith and the existence of God. One day, he receives a mysterious letter inviting him to a cabin in the woods where the horrific event is believed to have occurred.