The Dark Heart of Uukrul

Four adventurers are sent to the abandoned remnants of the once-great underground city of Eriosthé. Their mission, as stated by the Western Council, is to defeat the evil Uukrul, a dark magician of incredible power, who ages ago overthrew the Ancients of the city, and claimed all of its passages and caverns as his dominion. To reach the greatest possible powers, Uukrul detached his soul from his body, and stored his heart of dark stone somewhere within the furthest reaches of the maze-like passages of Eriosthé.
Your party of brave adventurers must find the heart of Uukrul and destroy it!

Source: TheGamesDB