From publisher blurb:
Ashes of the Plague of Shadows
Welcome to the world of Shadows over Vathak, a realm where the abominations known as the Old Ones seek to destroy humanity. It is a world of darkness and despair, where even the light of the One True God is often corrupted and twisted to serve sinister ends. As a GM your players could be heroes representing a bright point of light in the encroaching shadows of evil or they might just be survivors, getting by day by day however they can, survival their only goal. In Vathak, even joy is mingled with the bitter ashes of despair and hopelessness.
What you have here is additional GM information to augment the material presented in the Shadows over Vathak: Player’s Guide to Vathak and Shadows over Vathak: Player’s Guide to Ina’oth. New locations, monsters, and more are detailed in the pages of this book, tied to the plague-ravaged nation of Ina’oth. Even if your campaign does not visit Ina’oth, that does not mean you cannot use the material in this book. While the material here in is based on a specific region, it is also designed to fit the overall themes of Shadow over Vathak as a whole. As the GM, you should modify the material in this book as you see fit to create the story that you want to tell or the world you want to create.