Halls of the Blind is an optional quest in the catacombs on dungeon level seven in the original Diablo. It involves entering a room full of enemies that can turn invisible. It is initiated by reading the Book of the Blind, found on level seven. I can see what you see not— Vision milky, then eyes rot. When you turn, they will be gone, Whispering their hidden song. Then you see what cannot be— Shadows move where light should be. Out of darkness, out of mind, Cast down into the Halls of the Blind.