At some unknown point the Stanza was placed inside a copy of Otiluke's Icy Invocations and found its way to a sub-basement of the Readout in the Moonsea region of the the prime material plane of Toril.
The Archivists of Readoubt recently discovered that they were infiltrated by the Elemental Clergy. Their agent was named Mikuul Kern and in the process of finding the Stanza and fleeing the Readout, he murdered a fellow Archivist named Dolph Lunquist.
Kern was trying to translate the Stanza for the benefit of Prince Cryonax, when he was interrupted and forced to escpape from a group of adventurers sent by Primarchivst Franz without the document.
The Nulb Stanza is written in Flan, the aboriginal human language of the Flanaess on Oerth. It is purported to bring about the Apocalypse, its verses being a series a events that must occur, in order, to bring about the ascension of the Princes of Elemental Evil and ultimately sacrificing the world to the Elder Elemental Eye.