Beneath the Fetid Chelimber

From the introduction: The ruined wizard tower in the Marsh of Chelimber may hold a clue to defeating the superintelligent hill giant, Bad Fruul, and prevent him troubling the town of Parnast. To find the tower, adventurers must overcome the watery magic of the fetid marsh and discover or clear a route to the ruins of a previously lost tower. A Two-Hour Adventure for 1st-4th Level Characters.