The Book of Prophecies is one of the three holy books of the Gargoyles (the others are the Codex of Ultimate Wisdom and the Book of Circles). In it many prophecies are written down, with the prophecy of the False Prophet being the most important one. On the cover is a picture of a gargoyle standing triumphant over a fallen human.
The book had an immensely important role in Ultima VI. Iolo snatched it from the hands of the dead Gargoyle priest while rescuing the Avatar from being sacrificed. The Avatar showed it to Mariah after getting a clue from Nystul. She was able to decipher the title, but she needed the Silver Tablet to translate it completely. The Avatar, now knowing the motivations of the Gargoyles, tried everything from that point to save the Gargoyles from destruction. The 'sacrifice' the prophecy spoke of, in the end, was the Avatar's sacrifice of the Codex of Ultimate Wisdom to bring peace.
"An ancient prophecy tells of the final days, when the end of our world shall come. Three signs will precede the end. Thrice shall a being of great evil come unto our land, and by this it shall be known that the end is nigh."
"This evil one is of another race, who consider the evil one a great prophet. Yet this false prophet follows not the principles of Control, Passion and Diligence. One day the prophet will come and desecrate our most holy shrine. And the false prophet will steal our most holy artifact, the Codex of Ultimate Wisdom. This shall be the first sign of the end."
"Then, it is written, the false prophet shall descend deep into the bowels of the earth. And the false prophet will cause the underworld to collapse. This will cause great earthquakes to tear our world asunder, and there will be a time of plague and famine. This shall be the second sign of the end."
"One last time shall the false prophet come. This time, the false prophet will come with a band of warriors. And they will destroy all that remains of the gargoyle race."
"There is only one way that this prophecy may be averted: That is by the sacrifice of the false prophet."
- Quite interesting that the cover of the Book of Prophecies is a mirror image of the Game Box Cover of Ultima VI, where the Avatar stands triumphant over a dying Gargoyle.