The lower regions of Cul De Sac, which lie below even the Demon Tunnels, are a chaotic den of creatures that have escaped the notice of the ruling powers by virtue of obscurity. This is not to suggest that the area is without merit, just that it is in a sense, the sewers of the vast mesa above it.
In the section of the Undermesa, as it is most often referred to, a small degree of order has ariseon. It is important to remember that the lich, Rastigorus, who has carved out this small kindom was once the student of the great Daganai, right hand to Kazur and overseer of all matters in Cul De Sac. It is said that he wields the Spear of Daganai and has been a wizard for more than a thousand years. It is also said that he has no real clue as to how to use its full power.
When Daganai fell in 4252643, and Kazur briefly abandoned Cul De Sac for the relative calm of Ruzak Hold, Rastigorus fled to the dark regions taking the shattered remnants of several skeletal legions and became trapped in his own destiny, unable to muster any serious initiative or ambition for many years with regards to Cul De Sac.
The new overseer of Cul De Sac, Lordak of the Altesian Islands left to fight the Sons of Sestar and so Rastigorus flourished in the absence of any threat or ruling force and spread his will across more of the Undermesa.
Rastigorus has worked diligently to bring Daganai back from the vast wasteland dimension he was cast into, but simply has no clue as to how to accomplish it or any other possibly useful task.
It would be unwise for any intrepid seekers of fortune to confuse his relative incompetence with safety in this area of Cul De Sac for it remains a dangerous area, haunted by spirits, renegade skeletal soldiers, sorcerers unable to die and trapped in dessicated bodies, and an occasional demon. Lost and trapped creatures from the ground level such as dire wolves, dire rats, and an occasional antrodemus roam the halls devouring explorers and the local prey...