The Prophets of the Fire Heart is the first gold quest exclusive to Fable: The Lost Chapters, which begins after the battle with Jack of Blades at the end of the Fable main quest.
Walkthrough
Use Jack of Blades' mask to open the Demon Door at the Lookout point in Fable: The Lost Chapters. The door states: You bear the mask of Jack of Blades. The Prophets had foreseen the coming of such a legend among Heroes. The rise of the summoners in the Northern Wastes marks the arrival of a new threat to all things living. We have long dreaded this portent. Behind my walls lies the Fire Heart. There you will speak to the Prophets who watch over it. You may enter now. But beware the beating of the Heart. It has burned many before you.
Once inside the Demon Door you will walk into a crumbling yet once grand room. In the center of the room is the Fire Heart, suspended in mid-air above a tiled puzzle. Entrapped in shards of crystal are the five Prophets. They explain that in order to receive the Fire Heart you must first free them, and to do this you need to turn all of the tiles into suns, giving one of them their freedom. Then they warn that if you turn the tiles into moons one of them dies and you never get the Fire Heart. However, one of the other Prophets announces (much to his companions' dismay) that you will receive the Fire Heart regardless.
The puzzle must be completed five times; each completed puzzle releases (or kills) one of the Prophets. To change the tiles the hero simply walks across them. Once all of the Prophets are free (or dead) you will receive the Fire Heart.
