Edgewater's Folly

From publisher blurb:

Underground Adventure!

The city of Edgewater is under attack, though few realize it. Most just assume the rats and other vermin in the sewers have started spreading a new form of plague. They’re partially right — rats are spreading a virulent new disease throughout the city. But for those willing to plumb their filthy depths, the city’s sewer system holds many secrets. More is at play than just some filthy rats and a new strain of disease. Edgewater’s Folly is a 7th level Pathfinder Roleplaying Game adventure of heroic proportions!