A One-Round Living Greyhawk Regional Adventure set in Ket
From the introduction:
From the Yatil Mountains comes the horror army. Undeterred by the forces arrayed before them, the army bypasses all defenses and is headed directly into the Bramblewood itself. Can it be stopped? Should it be stopped? The dangers of the forest wait, possibly more so than they have ever been before. The penultimate adventure in the Natural Evolution Series.