The second part of Underfoot's "Unfolding the Lore" series gives us a glimpse into Pellucid Grotto:

The Pellucid Grotto is one of the areas of the Underfoot where the primal mineral underpinnings of Norrath and other worlds are managed. The race collectively known as the Crystalkin has made this their home since before memories were made.

Pellucid Grotto is a natural formation of colorful stones, where light shines through translucent crystal layers above great fissures in the ceiling, giving the area its name. Beautiful crystals thrust up from the ground of the caverns, emerging from the cave-like walls and acting as dim light sources. Other crystals, gems, ores, gasses, and substances can also be found throughout the Grotto.

The Geodech, the Crystalkin city, is dedicated to the implementation of Brell's vision through the efforts of the Crystalkin themselves. The town was built inside the cracked stony shell of the original geode-like "seed" which Brell brought forth to create this area. This part of the city is known informally as the "Upper City". Geodech's structure sits partially embedded in a large, hardened flow of obsidianite, called The Obsidian Scar, which is the main center of industry for the Crystalkin and where they refine and polish the gems which are to be taken to the Repository. The outer portion of the Crystalkin city is referred to informally as the Lower City, and the busier parts of this Lower City are arranged on the flatter areas of the Scar. The Upper City and the Lower City have been split recently by a wave of violence sparked by a third group of the Crystalkin deciding to leave the city in favor of following the Faith of Self. Tensions between the two groups are still high.

Surrounding Geodech, the Obsidian Scar, and other areas within the vicinity are outcroppings of a primal metallic material known as Euthorium. A great mass of Euthorium to the east of Geodech, originally part of a collapsed natural pillar, has been worked into a kind of natural bridge known as the Euthoric Bridge, which connects the central city with The Black Plinth. The Black Plinth is a prominent feature of obsidianite that serves as a landmark and as a ceremonial meeting place where the Crystalkin perform certain rituals.

The cave systems in this area are responsible for the creation of many of the gems found throughout Norrath. The Crystalkin harvest these crystals to make the gemstone seeds which are then sown into Norrath through The Repository. Within the Repository is a representation of Norrath where the gems are literally placed into the world by Brell's servants. The keepers of the Repository can change the floor map at any time to display a different portion of some other world; for now the focus is on Norrath.

Recently, the normally well-ordered reality of the Pellucid Grotto has come unstrung. The harmonious creations of Brell now find themselves in conflict, and the vital work of the Underfoot is suffering as vast portions of the Underfoot lay idle. The crisis may soon spread to other metaphysical realities, with catastrophic consequences for all.