It all starts with the murder of a United States Senator in a confessional, and the discovery of a strange religious document among his possessions. At the urging of his FBI friend, Jesuit Nicholas Branson joins the investigation. His effort to uncover the truth behind the murder draws him into a web of ecclesiastical and political intrigue, and sets him on a quest for an eight-hundred-year-old treasure that could shake the foundations of the Judeo-Christian world.