From the publishers blurb:
And to the undoomed living shall be revealed but a small portion of the horrid secrets the dead have hitherto so well guarded...and they shall quail...
Long ago, when the civilizations of mankind on the world of Ruil were small, petty things, the people of Ordane were visited by an extraterrestrial species known as elder things. Craving knowledge, these beings saw an opportunity to experiment, hyper charging the civilizational advancement of man towards their own ends. The elder things introduced the Ordanians to arcane and technological knowledge theretofore unknown to mankind. Ordanian civilization flourished, and its peoples worshipped the elder things as gods.
Eventually, Ordane came to be ruled by sorcerer-kings, powerful Ordanians with an insatiable arcane curiosity that would prove their downfall. Such was their might, the sorcerer-kings devised a means of making contact with the primal writhing chaos at the heart of the universe. Yet unbeknownst to the sorcerer-kings, they had reached Azathoth, the amorphous blight of utter confusion that transgresses angled space at the heart of creation. Azathoth immediately vacuumed all living denizens of Ordane to itself to be assimilated into the very energy of the universe. Utter dissolution was their fate.
Now, ages later, Ordane has long lain in ruins. Recently discovered by explorers from the colonial duchy of New Herod, it has gained the attention of powerful interests. The PCs are tasked with exploring the ruins and eliminating any threats. Rumors of goblins and bugbears in the area as well as a palpable miasma - an apathetic pall within the grounds of Ordane itself - are nothing compared to the whispers that...something...lurks deep within the bowels of the undercity...