This solo adventure book is set in the Forgotten Realms and is part of the CATACOMBS series.
From the back of the book:
ENTER THE WORLD OF THE UNDEAD!
Dirt fouls your nostrils and mouth as you reach the inevitable conclusion: You yourself, once a holy paladin, have become one the hateful undead! But you have no idea who you are or how you got here....
One thing is certain, however: Before you can escape your present state, you must stop the legions of undead, who even now labor feverishly to complete a monstrous underground construct that will spell doom for the entire population of Waterdeep and possibly all the Realms!
In KNIGHT OF THE LIVING DEAD, you enter the world of a visual maze, full of sinister surprises! As an undead paladin, you recover the pieces of the wondrous Staff of Waterdeep, but to complete the staff, you must explore underground tombs where fearsome undead creatures lurk around every bend! A unique feature of this book is your need to discover your Memory Traces, which will not only tell you who you are, but also may provide clues in your desperate hunt!
CATACOMBS Books represent the ultimate challenge in role-playing adventure. Through lavish illustrations, you journey from chamber to chamber in search of the precious object of your quest. Your analytical powers are tested to the utmost as you must decide how to deal with the weird and wondrous creatures and artifacts you encounter.