The Master Index

The Master Index is a huge, leather-bound tome of immense size. It sits upon an ornate stone and gold-work pedestal in the center of The Cathedral of Knowledge. After completing an arcane ritual near the precipice of this artifact, one can procure the key to the eight doors which lead into The Nine Great Libraries, excluding entrance to The Library of Blood, of course.

Some say The Goat King tried to steal this book, but was mortally wounded, retreating into solace for many hundreds of years in order to restore his skin.