Curse of Xanathon (Dungeons & Dragons Module X3)

"Something is rotten in Rhoona... When the grotesque god, Cretia, casts his ugly shadow over the town, strange things start happening. First, Duke Stephen vanishes. Then bizarre proclamations begin coming out of the Ducal Palace... dwarves are outlawed... taxes must be paid in beer,,, horses must be ridden backwards. Soon the entire town is in an uproar and a dwarven army is marching on Rhoona. This is the situation when you and your party of valiant adventurers arrive in the suffering town..."