"The Pinch"
by Vanya Dae'ia
The Chamber
Beneath the ruins of old Stonehold, known to many but accessible by few, is a curious chamber occupied by an apparatus of unknown origin and function. This massive crystal, suspended high above the narrow walkways of the chamber, emits a powerful but unstable field of magical energy. Near it lies a source portal, which has become a hub of transportation for Wharftown, Brogendenstein, and Myon.
Below this upper chamber is another, nearly identical, but in a state of disrepair. It holds an identical apparatus, as well as a source portal linking to the ley-lines which pass through The Underdark. [Here follows a neatly drawn diagram of the chamber, itself: A circular room with a low flat floor, above which are extended four stone walkways, connecting to a central circular platform. At the outer edges of the chamber, each walkway leads to a round alcove; one contains a glowing portal, two hold staircases leading above and below, and the last is caved in. From the edges of the platform, four sharp spires rise, and from them a set of stone arches come together to a round center, where a massive, faintly gleaming crystal hovers. A sparking and sputtering shaft of light pierces downward from the crystal, and into the lower chamber. -- The lower chamber appears the same as the upper, with some rubble and root growth around the portal alcove. Its floor is far deeper, and flooded with murky water.]
The Faerzress
A Xanalress word for a type of magical radiation found in The Underdark. According to historical manuscripts, it is believed to be a remnant of the magical forces used by the gods to shape The Underdark. What can be definitively proven about it, through experimentation, is that it interferes with magic.
Any experienced Mage who has passed down into the bowels of Toril can attest to the problems that this unseen barrier causes. Wards are stripped and broken along the way into these deep places. Even the most powerful of Diviners cannot scry or see through the barrier. Likewise, Conjurers cannot summon subjects through the Faerzress.
Arelith's portal system is impeded by this barrier, as well. The natural ley-lines, though they may pass through the Faerzress, cannot support passage through it. While an individual may be attuned to a destination portal in The Underdark, they will not be able to see it from above, and thus will be unable to reach it.
Because transportation via ley-lines appears to be relatively uninhibited in Arelith's Underdark, it can be assumed that the local Faerzress field is most concentrated in a layer just below the surface.
The Pinch
We have seen that the Faerzress causes problems with ley-line transport, and yet these two chambers, which are in relatively close proximity, each house source portals. From this and the other relevant culled evidence, I hypothesize that the apparatus shared between these two chambers is "pinching" the Faerzress field, compressing it into so thin a layer that the ley-lines of both the surface and Underdark can be accessed only meters apart. I further hypothesize that the true purpose of the apparatus is to pierce the Faerzress entirely, opening a conduit between these two disparate locales for magical transportation, summoning, and sight.
Such a conduit would benefit Arelith's people with opportunities for faster and safer exploration of Toril's depths. However, it would also serve as a means for the vast hordes of The Underdark to pour out into the cities in pursuit of conquest. Perhaps it is for this reason that the apparatus was built. And, perhaps it is for this reason that the apparatus no longer functions.
The identity of the apparatus's creator remains a mystery, as does its true purpose. Informed conjecture appears to be the only means by which we may come close to understanding it. Hypothesis, however, is the first step in the pursuit of knowledge.