From the introduction:
Ar’Goriath, feared and respected in equal measure, was a wizard of great power known for designing and building the grandest and most dangerous monuments, tombs and dungeons for the mightiest of kings and emperors the world over. Rumors swirled that his renown was so great that even beings of other planes commissioned his works. In his later years, he went mad, again fueling rumors of his congress with Those Men Should Not Meet. His power remained, however, and he foresaw his own death. Desiring to keep his riches from other mortals, whom he detested as inferior beings he had surpassed, he built his final dungeon; a grandiose tomb to hide away the worldly treasures he left behind. Legends say his spell books and artifacts of mighty magic are sealed away in the innermost secret chamber of his tomb, though none have yet found them.