And so we begin.
Poughkeepsie, NY, USA a.k.a. "Fray", "the Bubble"
Poughkeepsie is a smallish American city of about 30,000 people located in New York State; it's a river city, with a history stretching back several centuries. Humanity doesn't have much to say about the place; in the mundane world it's mostly known for its mildly memorable name and Vassar University. In other words, to mortal eyes the city is not particularly noteworthy and hardly especially significant. To celestial eyes, it's a place of horror - and we're talking in-space-nobody-can-hear-you-scream style horror.
As near as anyone can tell, it all started on August 23, 1908, when an otherwise routine reconnaissance mission resulted in what the research metaphysicians call a 'cascade'. As has been noted elsewhere, the primary result of disturbance is the rewriting of reality in the near vicinity: generally speaking, the larger the disturbance, the greater the rewrite. Presumably, that is: given that celestials are equally vulnerable to the effects, it's actually a bit hard to tell just what happens. Cascades are simply rewrites large enough that people notice the flotsam.
To complicate matters further, this was an anomalous cascade, albeit with a rather flexible definition of 'anomalous': in this case, the reweaving process that the Symphony uses to repair itself has stalled, apparently permanently. There is a metaphysical blank spot - globe, actually - five miles in diameter and centered on the shore of the town. Inside that globe, nothing supernatural works. That means no resonance use, gathering or expending of Essence, Song use, imposition of dissonance conditions, celestial combat (or even taking celestial form), long-term maintenance of vessels not specially designed for the specialized environment, any sort of Undead, Superior invocations: nothing.
Luckily for the human beings actually living there, the old wives' tale that when a person dies his or her corpse loses a quarter's grain of weight is quite true (in this universe, at least); souls have a physical component, so anyone who dies in Poughkeepsie is not instantly subject to the True Death. On the other hand, anyone who dies in Poughkeepsie is not automatically sent on to Heaven, Hell and/or reincarnation. They have to leave under their own power... and, given that they aren't Ghosts, either (with a Ghost's stubborn drive and focus), the will to do so is quite often not available. The result of this is that the least supernatural section of the corporeal universe also has one of the highest concentrations of apparitions and spooks. Generally speaking, they don't do much, but their relative presence triggers human subconscious attitudes; the town 'enjoys' a reputation for being boring, stodgy and - tellingly - dead. Aside from that, it's interesting to see how little things change when angels and demons are taken out of the picture; the town is not notably worse or better off for having no celestial oversight - which is actually quite odd, given that human beings are unable to even unconsciously spend Essence while inside the Bubble. Perhaps everything balances out in the long run.
As noted above, celestial vessels not designed for the place tend to degrade over time. Most vessels aren't really designed to work the way that a real body would; trying to keep muscles working when they're being supplied by a digestive and circulatory system that's largely ceremonial isn't exactly easy. In game terms, every 24 hours spent inside the Bubble will cause one hit of damage to a vessel, and there's no real way to for celestials and/or ethereals to properly heal damage while still inside the no-supernatural zone. They can stop bleeding and set bones, and that's about it. The only two exceptions to this are Grigori and Lilim - the former supposedly are both immune to the daily damage and can heal normally there, while the latter seem to just be able to 'encourage' their vessels to take on a functionally human aspect. It should also be noted that both Nephellim and Gorgons immediately lose all of their supernatural aspects while in the Bubble... which can include their Disadvantages. They may still suffer lingering physical effects, but not many crossbreeds care.