In one of my stories Ive used kind of Resonance well (also this place had Mana Void, those things just dont stack in my mind) near false magnetic pole on Madagascar - mountain full of iron etc. There was an ancient ruin on that mountain, hidden in the stone labyrinth (each layer of the labyrinth was -1 to mana down to 0) and in those ruins, there was top secret archaeological site with elevator leading very very deep into the Caer from 4th world (with -8 Background, +8 Resonance well)
Based on the Earthdawn adventure Deep troube (IMO in the Throal Adventuures soucebook, but Im not sure right now), I kept most settings the same as it was for the dwarf city noted there, with a few changes: Hi-tech cyberware, electronics and weapons facilities in the core base of the city, surrounded by impenetrable darness. Explorers cooperating with free sprite do decipher what they can from ruins all around (since this Caer has fallen) they havd explored some distant corners, well not everything. City is rued by the court, and most tech is in hands of technomancers who are keeping tech running: one operating geothermal powerstation, one operating drone facility and one operating Cyberware facility.
Why and how team get informations on this site, and why they had visited the place itself is irelevant, well during their stay they were asked for a favour...as the outsiders who are able to keep their mouth shout their were sent to reestablish automatic perimeter and rebuilt geo turbine in the area with underground water reservers, that were vital for the "city". Due to EMP stormsoutside proective field aroun the base, kept by technmancers, the were moving only slow, tracing their way with laser link transeivers in poles.
The hiden quest inside of this was to explore the area, following previous team disappeared and reported as dangerous by other stalkers, explorers and independet scavengers.
Not that they met some hororr scenes during the way etc.
Finaly they fount the cave...place...like silicon hell...where resonance itself materializes in form of crystals and wild sprites were able to materialize, using EMP and electricity attacks based on offensive programs.
In the deepest cave they found remains of waste battlefield and also remains of the Horror slain here eons ago. His material form destroyed and his spirit trapped in manavoid, he slowly become resonance being, shaping and altering everything around.
Technomancers, playing false game on the base inhabitants, were from disonant tribe, responsible for most ECM in the area (which they called Resonance storms) were trying to help the
Genius loci to find its way to manifest itself in some kind of Resonance being...maybe the first Resonance Horror entity
The rest is history...treason, trap, imprisonement escape, revelation, constant struggle for survival and final cataclysmatic battle...standard shadowrun...
