After a recon mission into the Slags Hograth writes a letter to his superiours:
wrote: To: Mover Oroak, Harmonium
From: Measure II Hograth Thorn, Harmonium
Sir,
our mission into the Slags was sucessful and we recovered vital information.
Most important is the following fact:
The Cerulean Sign can be used to both repel the invaders as well as detect possession as possessed beings will recoil from it.
We also found an Illithid sage, well learned in all matters concerning the Far Realms who we could persuade to cooperate with us. It hinted at the invaders trying to make our reality more similar to their own and suggested to destroy all things tainted by them, burn corpses that have been possessed ect.
There are also survivors there, hiding in an old Anarchist outpost.
*a description of the place following*
I suggest one of our patrols closes this place down as soon the current crisis is over.
Kala Ta'Kan, a godsman factotum might be able to create a permanent glyph which has the same effect as the Cerulean Sign spell and I suggest to at least get one of those installed in the entrance hall of the barracks.
Hograth Thorn, Measure II
<a seal showing a Dragon's Claw and an arcane mark showing something similar>
Then he writes another note to inform Chari- knowing well that information sometimes travels slowly along the chain of command:
wrote: Measure Chari,
The Cerulean Sign holds them at bay. Possessed creatures shirk back from it as well. Lets use this to our advantage.
Hograth Thorn.