Sewers of the Rat King is an urban adventure designed for a party of three to five players of level 1-3. The adventure was intended to take place in Waterdeep, but can easily be changed to set in any urban location.
A group of adventurers find themselves in Waterdeep where five different people disappear nightly never to come back, yet the lords of Waterdeep struggle to take action. When a noble's only son disappears, he hires the adventurers to find him.
During their unsuccessful search for clues, one of the adventurers is captured. The adventurers discover the kidnapper is a wererat and his lair is deep in the city's sewers.
While crawling through the sewers, they find the captured prisoners have been infected with lycanthropy and turned into members of some kind of wererat army.
While trying to escape, the heroes are attacked by what seems like the leader of the rats and his mob of wererats. To escape and free the kidnapped prisoners, the heroes must defeat the lycanthropes.
- from the publisher's blurb