QUOTE(Olav @ May 13 2006, 06:25 PM)
It's part of one of the Mages guild initiation quests. It has two parts.
Well, this is the spoiler section, so you can be more specific.

It's the recommendation quest in Chorrol, where you will have to find the ''Finger of the Mountain'' book. Then you have two choices: To give the book to Argonian who will write you your recommendation right away, or a woman who dislikes the mage's guild. Don't give the book to Argonian. Instead, the woman will provide you with instructions to get yourself a powerfull spell, called ''Finger of the Mountain''.
To get the recommendation later, you will just have to steal the book back from her.

But as Olav said, the spell is leveled so it isn't very useful.