The Prophecies of the Final Day is a work of prophecies in Sanctuary. It's most likely located in one of the libraries of Caldeum, but exact information is currently unavailable.
Excerpt
A Wanderer will pass through the ancient lands trailing chaos in his wake.
The Three Brothers will be reunited as the mortal world trembles before their might.
And so it was foretold that the Three, once reunited, would be shattered again—
And the last of them would set his sights on the holy mount. The warnings held that
Their defeat would be illusory—that the final gambit had yet to be played..."
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And now at last the storm surges forth from the southlands, and the hand of Destruction
Reaches out to undo the workings of the Ancients. The tides of Hell surge — ready to smash
Down upon the shores of the mortal world—to drown the guilty and the innocent alike.