From the publisher:
He waited, standing like a statue just inside the entrance of the Administration Wing. He had not moved in a thousand years, having no need of food or rest, and never suffering from fatigue. He existed to serve his master, which gave him pleasure. And every moment of those thousand years was pleasing, for his Master had bid him to wait.
Then a whisper of thought brushed his mind. His eyes regained focus and he turned his head, recognizing the pyramid of mummified Harlass Orn corpses he had carefully assembled so long ago. He sensed his Master’s voice, faint yet unmistakable. The rift had opened again, and Agurth-Plaga called to him.
Months have passed since the Harlass Orn were freed from the Veilwalker Dreamseeker in The Dreamers Awaken adventure. One of the survivors, the scholar-mage Zzhastor Brune, learns that the people of Kith’takharos have begun using the ancient Harlass Orn Teleportation Towers. These towers precipitated the Harlass Orn downfall, for the magic employed in tower teleportation opened a rift that allowed the extra-dimensional Veilwalkers to enter normal space and destroy the Harlass Orn.
Brune fears that the rift has been reopened, and knows of only one method that might seal it before the Veilwalkers once again overwhelm the swamp. Someone must enter the Harlass Orn research facility called Nhamah and retrieve the Aether Bind, a device designed to close the rift.