In the Age of the Ancients the world was yet unformed, shrouded in a fog. A land of gray grags, Archtrees and the Reign of Everlasting Dragons; but then there was Fire and with fire came disparity. From the Dark THEY came and claimed the Souls of Lords from the Flame. The Heretic Kai of Nirn and his Burned Cabal, Ruebeth and her Grimoire, Gerhardt, Conqueror of Light, and his legions, and the Furitive Pygmy, so easily forgotten.
With the strength of Lords they challenged the Dragons. Gerhardt's Mighty blade cleft through the Dragon's stone scales. The Heretic Kai scorched the land with his righteous fury. Ruebeth tapped eldritch powers, spreading death and destruction in her wake. Soon the Dragons were no more.
Thus began the Age of Fire. But soon the flames will fade and only Dark will remain. Even now there are only embers, and man sees not light, but only endless nights. And amongst the living are seen, carriers of the accursed Darksign.
Yes, indeed. The Darksign brands the Undead. And in this land, the Undead are corralled and led to the north, where they are locked away, to await the end of the world... This is your fate.
Only, in the ancient legends it is stated, that one day an undead shall be chosen to leave the undead asylum, in pilgrimage, to the land of ancient lords.