Ultima Underworld Clue Book



The Ultima Underworld I Clue Book (also known as "Mysteries of the Abyss") is 64 pages long and contains game narrative and maps presented by the evil wizard Tyball, 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.