The Book of Nagash is the foundational grimoire of all necromancy, the black tome in which the first and greatest necromancer set down the secrets of undeath — and perhaps the single most dangerous object ever written in the world. Its author, Nagash, was a priest-king of Nehekhara who stole the death-magic of the elves, twisted it into the art of raising the dead, and drank an elixir of warpstone to make himself immortal and undying.
In its pages lie the incantations to reanimate corpses, bind spirits, drain the living, and cheat death itself. Nagash's own dark rites, cast from the working of the Book, corrupted the funerary magic of the Liche Priests and doomed the whole of Nehekhara to rise as the shambling undead of the Tomb Kings. When Nagash was cast down, his knowledge did not die with him; copies, fragments, and corrupted transcriptions of his work passed into the world.
From these scattered writings springs every necromancer and every vampire lord who has ever plagued the living. The Vampire Counts prize the Books of Nagash above any treasure, for whoever masters them can raise armies from any graveyard and bend death to their will. To read the Book is to be forever changed by it — to gain terrible power at the cost of one's soul, and to take one's place in the long, damned lineage of those who would make themselves masters of the dead.