The Achturardackians were pioneers of sigil based magic, and their techniques for building glyphs, sigils and seals remain the foundation of magic inscription.
The relic of an old Sorcerer, the Glyph of Tarnos Krae is a window into the past.
With regard to the plot "Sleeping Mines of Elathon":
You manage to get the water wheel in the mine working which operates a pump to clear the flooded lower levels. As you explore the dank tunnels of the lower galleries, you can hear the creaking of the wheel above. You enter a low-ceilinged passage and are crawling on your backs, when the creaking stops. The water starts seeping wetly around the back of your head...