From the back of the book:
Pestilence and plague... twin beasts that even the most stalwart adventurer fears... Plague threatens the river village of Bhorr's Bend, deep in the forests north of the City-State of Shyff. Dark secrets lie hidden within the doomed village; can the truth cleanse the folk of their dire disease? Can the characters stop the spread of the Plague before the Prince of Pestilence stalks the Sovereign Lands?
This adventure is designed for use with four to six characters of 3rd through 5th level, though it can easily be adapted for use with any mid-level to high-level adventuring group. New and complete rules for running diseases in fantasy settings are provided, including descriptions of more than half a dozen new fantasy diseases.
The Night of the Rotlord Kalamar Quest adventure and supplement is designed to provide both a challenging adventure and useful supplementary campaign material. The material within is set in the popular Kingdoms of Kalamar fantasy campaign setting but can easily be used with any fantasy role-playing game setting.
This game adventure and supplement is suitable for use with any fantasy role-playing system, including but not limited to Advanced Dungeons & Dragons, Rolemaster and HackMaster.