From the back cover:
"Barony of the Damned is a stand alone adventure for Warhammer Fantasy Roleplay, designed to breath life into one of Bretonnia's more infamous lands. In addition to the adventure, this book details the Mousillon, its history, its people, and politics. Inside you'l find several new monsters like the Grey Men, new diseases such as the Red Pox and Swampaire's Croup, and two new careers: the Frogwife and the Swampaire. In addition, this book presents statistics and information on all the important characters found in this foetid land.
Can the heroes survive the terrors of Mousillon long enough to bring back the head of Guido LeBeau? Find out in Barony of the Damned."