This is a Dungeon Crawl Classics adventure set in Lankhmar for level 4 characters by Goodman Games.
From the publisher:
Votishal the Silent is on the rise! Ascending from antiquity, the religion threatens to dominate Lankhmar’s Street of the Gods. Alas, something is killing the clergy! Desperately offering a fortune in reward, they’ve abandoned their temple. But it is by no means vacant. Intrepid souls must face nickers, alley-bashers, and magical guardians, while avoiding sinister traps to uncover the building’s secrets. Even the sewers have something to hide. Only keen minds and blades can stop the violence for Votishal!
Officially licensed from the estate of Fritz Leiber.