Ultima Underworld Clue Book



The Ultima Underworld Clue Book: Mysteries of the Abyss is 64 pages long and contains game narrative and maps presented by the evil wizard Tyball in a letter to his former apprentice Malabelle, and the Avatar, plus details on the game engine of Ultima Underworld. It originally retailed for USD$14.95 and was published in 1992. It was written by Aaron Allston.

This was the first hintbook to be assigned an ISBN code.