The Refracted Seal of Orizon

This perfectly octagonal chamber is lined with floor-to-ceiling silvered mirrors that hum with a faint, low-frequency vibration. In the center of the room, a pedestal holds a rotating obsidian prism that catches a single vertical beam of white light falling from a hole in the high ceiling. The air is unnaturally still and smells of ozone, while the walls are etched with glowing blue glyphs that only appear when the prism's light strikes them directly. The floor is made of polished black marble, showing a perfect, distracting reflection of the ceiling and anyone standing within.