Separating fact from fiction, Secrets of Angels, Demons & Masons is the ultimate guide to the secret societies of Dan Brown's thrillers. Based on Dan Burstein and Arne de Keijzer's best-selling book, Secrets of Angels & Demons, this two-part documentary investigates the Illuminati and the Freemasons, two mysterious organizations central to Dan Brown's novel Angels & Demons as well as his upcoming sequel to The Da Vinci Code.