Lich of Lost Boy Cavern

The Lich of Lost Boy Cavern
This is a quest that does not appear in your Journal. The quest begins when your character discovers Lost Boy Cavern, and a nondescript journal lying outside. The journal tells of a man named Vangaril, who entered the cave prior to the player to seek out an erstwhile friend named Erandur, who has turned himself into a lich. Having tried and failed to recruit the assistance of the Mages Guild, Vangaril sought out to save his friend's soul on his own.

As the player traverses the cave's great emptiness, several notes are discovered littering the floor, ranging from a personal note left by Vangaril demonstrating a rhyme he used to memorize his safe passage through the darkness, to a threat left by Erandur stating that he will, "...consume [Vangaril] from within."

When the player enters the deepest reaches of the cavern, named Lost Boy Hidden Bastionafter encountering various enemies ranging from necromancers to myraid undead, a secret bastion is revealed, in which resides the Lich of Lost Boy Cavern. Upon slaying the lich, who drops a leveled staff, the player may notice (behind a throne upon which resides the skeltal remains of whom the player may assume to be Erandur), a chest locked with an 'average' level locking mechanism, and a note upon it, proclaiming of Vangaril's supposed "success" in vanquishing the lich and exorcising its presence from Erandur's body. Having been expelled from the Mages Guild due to accusations of necromancy, Vangaril was far too inexperienced to properly banish the demon. The note goes on to say that he will now search the cavern for such treasures as he may find to appease the mages of the guild.

Continued exploration yields further documents. Upon a table, which also dispays several tools of necromancy, as well as a severed head, (identical to the head which appears in the Dark Brotherhood quest Following a Lead) resides three notes to the mages guild, two of which have been hastily crumpled and cast aside. The first is a respectful missive, named "An Open Letter to the Guild of Mages," informing the guild that "an evil has taken root in [Vangaril]," and then abruptly stops, as the writer had discarded it.

The second is a tad more agressive, titled, "A Letter to the Once Great Guild of Mages," saying that it is their fault that he was inexperienced in his work, and that for his subsequent possession they are to blame as well. This note as well trails off suddenly, before the writer finally began their completed message.

The final note, "An Open Threat to the Guild of Mages," is written in a blatantly angry hand, threatening their downfall at the hands of the lich ErandurVangaril and the necromancers. It goes on to mention both Kvatch and Mannimarco, then finishes with a string of daedric symbols.

Trivia
The note, "An Open Threat to the Guild of Mages," mentions Mannimarco, also known as the King of Worms, leader of the Necromancers cult, as seen in the quest, Confront the King.