The Bookshelves in the under ground area in Hrodulf's Home is actually a Secret Door which opens up this tunnel
Activate Bookcase to gain access.
See screenshots below for tutorial on finding the secret hall:
The Bookshelves in the under ground area in Hrodulf's Home is actually a Secret Door which opens up this tunnel
Activate Bookcase to gain access.
See screenshots below for tutorial on finding the secret hall: