There is a lich who dwells on the island in Brightwater Lake to the north. Although he is a free-willed Forsaken, he believes all other Undead are Scourge slaves and has his minions attack anyone who approaches him.
But because he is Forsaken, the Queen will want him. And if he is skilled in Necromancy, then his knowledge would be...quite useful to us.
To discover his identity and his talents, I must see his spellbook. Steal into his camp and acquire it, then return to me.
Very good, <name>. I will study this book and determine the identity of that lich. You have served your Queen well.
Astonishing! The book you retrieved belongs to no one other than Gunther Arcanus!
Gunther was a skilled Necromancer in life; he and I were friends and comrades-in-arms, before the Plague. And judging from his book he has grown even more powerful in death.