Book Four: Revelations is the fourth part of Dreamfall Chapters. Between Books 3 and 4, RTG ported the game to Unity 5.2 – a prerequisite for the impending PS4 version and a necessity to profit from further Unity patches. It was released on December 3rd, 2015. Expanding on the saga of The Longest Journey and Dreamfall, Dreamfall Chapters is an episodic adventure game about choice and consequence, about dreams and reality, magic and science, chaos and order, and about the people whose actions may change the course of history in all worlds.