Devouring Plague
Speak to Aelthalyste in the Undercity.
Description
Ah, a wonderful day for you, <name>. I can see by the lessons you've learned that the time has come to send you back to Aelthalyste. There are things only she can teach you, and even then, only if you prove worthy.
I will not spoil the surprise for you, but I remember when I was a young priest learning about true power... divine power. Yes, those were the days.
Go back to Aelthalyste in the Undercity, <name>. She will be awaiting you in the War Quarter.
Completion
I would teach you Devouring Plague if you feel you are prepared, <name>. A spell of no small power, it will aid you in your coming battles. Practice with it--there will be tests later.
Rewards
You will learn: 
Devouring Plague (Rank 1)