I just finished Shurugeon Castle and then picked up the next Mage Guild quest. It requires I pick up Ardibren's relic from the Castle.

I've gone back but cannot seem to find it. Can someone tell me where it is?

Thanks.

I think it was in his library...make sure you didn't already pick it up and accidentally sold it to a merchant in town.

What library??????

His library was the room in which you used the Magus Key to open up the bookshelves. The relic is in a chest in a room through the bookshelf that opened up. Follow me?

{Specifically}

Open the bookshelves... go through. Go down hall, enter room. Open chest, get nice things. Identify. Ardibren's is what you're looking for.