This place was a very sinister hall.
The dim and obscure shadows, the strangely-shaped stone carvings, and the twisted, mysterious patterns etched on the walls all around, along with the suspicious red paint on those patterns, all came together to fill this subterranean hall with an air as if it were the headquarters of some evil cult.
In the center of this gloomy hall, on the ground, there was a hexagram pattern about ten meters in radius, drawn in silver-white lines. Gold lines and gemstones representing planets adorned the constellation-like objects, distributed in some hidden order among the eleven triangular zones divided by the hexagram. However, if someone knowledgeable saw them, they would realize that these patterns were unheard of—their shapes may resemble constellations, but what they depicted was definitely not any constellation seen from Earth.
