A One-Round Living Greyhawk Shield Lands Regional Adventure
From the introduction:
Attempts to contact survivors inside the Tower of the Shield Mages in Admundfort have failed to breach the arcane defenses for months. The search for remaining Shield Mages outside the tower has yielded no one. The PCs are given orders to follow up a reference from a now-deceased Shield Mage’s diary. The trail leads deep into occupied territory to the edge of the treacherous Great Effluvial Swamp!