The Shadows, also called The Grave’s Threshold or The Between, is a liminal space between the other planes of existence. It’s the lubricant in which the gears and pistons of the Great Mechanism do their eternal dance. It buffers one from another and prevents potentially catastrophic impingement.
While the name suggests twilight and darkness, a lack of color or life, that is not a true depiction. The Shadows are a projection of the other planes onto the Mortal plane and vice versa. In the Shadows, all the creatures of reality mix and mingle as do their hopes and dreams.
Matter and Spirit in Shadow
Unlike the Astral or Abyssal, where physical, condensed-anima bodies are difficult to maintain, physical existence in Shadow is normal. Unlike the Mortal or Elemental planes, where aethereal bodies of diffuse anima held together by will are difficult to maintain, aethereal bodies are functional in Shadow and can interact normally with physical bodies by accreting a layer of shadow anima as an interface.
Shadow anima is the basic material building blocks of the Shadows. It responds to the conscious (and unconscious!) desires and will of sentient beings and takes physical form, forming bodies, buildings, rivers, and everything else on the plane. Shadow anima is much more fragile than the more elementally-aspected anima native to the Mortal and Elemental planes—without constant attention from a Spark (a mind), it reverts back to formless amorphia.
Travelers from the Mortal or Elemental planes who visit in their true bodies find themselves changed by long exposure to shadow anima, especially if they consume food made of shadow-stuff. These changes manifest first as sensitivity to the searing light of the Mortal sun (which disperses shadow-stuff), but that fades quickly as you re-acclimate to the more “real” Mortal anima. Progressively longer exposure replaces part of the subject’s body and soul with shadow-anima. This grants new and strange powers, but leaves one very vulnerable and at risk of total dissolution on return to the Mortal plane. The Cysgoroesi (shadow elves) have developed a method of avoiding these problems, but they do not share it with outsiders.
The first part of Shadow experienced by travelers or departed spirits is the Borderlands. This is the “true” plane of Shadow. It extends throughout the Crystal Sphere and the knowledgeable can use it to transition easily between the planes. In the Borderlands, time does not move the same as it does in the other planes. In this silvery void, bereft of any physical object except the predators and prey that call this strange place home and the solitary Colorfields Fortress of the Cysgoroesi, time and space flow in tides and currents. Get caught in the wrong one and you might come out thinking a few seconds had elapsed but finding yourself a decade later, in an entirely different part of the Crystal Sphere. Or the reverse—you may spend a lifetime in the course of a few seconds and travel thousands of miles, only to find yourself where you began.
Physical egress from the Borderlands happens via color pools. These shimmering portals range in size from a few feet across to many dozen yards. While the color patterns tell experienced Shadow travelers what plane they exit to, the exit destination within that plane is uncertain. Color pools are transitory in nature—both the destination plane and the location within the Borderlands are subject to change. The only partial exception is the Color-fields, a region where there are dozens of quasi-stable portals overlooked by the largest of the Cysgoroesi fortress monasteries.
Travel through the Borderlands happens by conscious thought—you do not walk, instead you will yourself into motion. Beware of distraction, because the entire space is sensitive to your thoughts and you might find yourself facing your most carefully-hidden fear, made flesh by your unconscious mind.
The Borderlands is inhabited mostly by the restless spirits of the dead as they quest for a stable place in one of the other layers of Shadow and by the predators that feed on them. Shadow-sharks prey on the spirits of fish (and on more human spirits), star-spinner spiders weave webs of shadow to trap the unwary, etc. The only permanent sapient inhabitants are the Cysgor, who staff the Colorfields Fortress and use the Borderlands as a means of travel between the planes.
The Other Layers
Unlike the Borderlands, which extend throughout space, the other three “layers” of Shadow only exist in pockets surrounding the inhabited worlds as they are the effect of the collective unconscious of the inhabitants of the worlds themselves and are shaped by the beliefs, hopes, and fears of the populace. They are co-existent and more akin to states of being rather than physical places. Three layers surround Quartus—Mirrorhaven, the Dreamlands, and the Waste (although this is not a full layer in and of itself). The convention among the learned is to treat them as if they were stacked vertically, with Mirrorhaven on top, closest to the Astral plane in the common depiction and the Waste on bottom (nearest the Abyss). While this is false (as the layers are all jumbled up in reality), it provides a workable model of the inter-relationships with the other planes.
In many places around Quartus, the the Borderlands is very thin and most who step through the Shadow Veil (whether in dream or in the flesh) find themselves seamlessly in one of the layers. Which layer depends on both the location (some areas are more attuned to one layer) and on the person’s own heart. This is especially true of the dead, who are drawn through the Veil and usually find themselves in the layer that best fits how their hearts and souls were attuned. This is not heaven or hell, not reward or punishment. Merely the attraction of like with like. The layers are not good or evil, merely different reflections of the Mortal plane and mortal hearts onto the other planes.
Each of the layers has a landmark location, a hub, if you will. This center of the layer contains what government exists (although none of them are dominant across the layer) and is the epitome of the nature of the planar layer. Each layer also is home to one or more of the Cysgor fortresses, some of which stand abandoned.
The bright mirror of the Mortal, Mirrorhaven is influenced by and partakes in the flow of energy from the Astral plane. Its nature is of bright colors, constant movement, and frenetic interplay of light and color. It is home to the Summer Court of the Fey, the assembly of spirits attuned to the “positive” emotions such as love, joy, devotion, pleasure, and the like. Do not be fooled by the names, however. Also associated with this layer is mania and illusion; nothing here is as it seems. Delusion is rampant; everything wears multiple faces. Decadence and lavish excess hide a hollow, insatiable hunger that cannot be filled—the shadow-stuff of which this is made is not stable or real enough to satisfy. The inhabitants continually search for greater and greater sensation to fill this numbness. The majority of the populace is the spirits of those departed mortal souls that were attuned toward the Astral, either as a life of devotion to the Gods or for personal reasons. Here they live a distorted reflection of their lives until either they lose track of who they are and dissolve into shadow-stuff, until they are devoured by one of the denizens, or until they press through to the Astral plane itself and carve out a residence there through transcendence.
The hub of Mirrorhaven is Centrum. This city once was the capital of the Western Empire of Noefra until a tremendous magical explosion threw it into Shadow about 800 years ago. The inhabitants have become shadow-kin, beings made of shadow-stuff. All the decadence, excess, and mania of the layer are most concentrated here—the entire city is one continual, frantic, eternal festival. Souls drift in and are caught up in the celebration. The weak burn out quickly; the strong prey on the weak for survival.
The Dreamlands are the “dark” counterpart to Mirrorhaven. Where Mirrorhaven is attuned to the Astral, the Dreamlands are attuned to the elemental and the primal. This is the home of many of the fey, but especially the Winter Court. If Mirrorhaven is manic, the Dreamlands is soporific. The daily routine, the static sameness, the wilderness. If Mirrorhaven is deceptive, the Dreamlands is forthright in its madness. Here, the risk is depression and apathy. After a while, nothing seems to matter and the soul drifts into sleep. The spirits that find themselves here are those that were attuned to the primal, to the kami or to the elemental planes. They drift into slumber and disintegrate, meld with the layer, or force through to the Elemental and form bodies there.
The hub here is the Dream Titan’s Throne. This enormous (and physically inconsistent) castle, seemingly made of wood, rock, and bone changes from day to day; its inhabitants (mostly the fey) migrate around from “room” to “room” lest they get swallowed up in the dream and never awaken.
Unlike the other two layers which coexist naturally (locations in the Mortal plane mapping nicely to locations in both layers), the Waste is an aberration, a scar that cuts through Shadow. Wherever the Mortal plane was strongly touched by the Abyss, there in Shadow a pocket of Waste forms that blurs the layers together. This is a foothold of demons, a passage into the Mortal plane. It grows and shrinks, struggling against the other layers which try to contain it. Largely barren, what little life exists here is twisted and altered by the pervasive abyssal influence. The souls that end up here are those who were tainted, whether of their own accord or by the actions of others, by the abyss. Most of them reject the abyss and struggle against it. Some are consumed by demons as fuel, others who succumb to the corruption become demons and turn on their fellows. Others burn themselves out fighting the demons and the corruption. A few escape to the other layers or planes. Very few exist for very long after death, however. Unlike the other layers, life here is hard enough and the plane itself lets them be. Thus, Wasters are among the most sane of the inhabitants of shadow, not prone to the self-delusion or mania of Mirrorhaven or the apathy and indolence of the Dreamlands. Devils are often found here in force, playing their cosmic role as the opponents of demonic forces. Former mortals and fiends mingle freely.
The hub here is the Demesnes of the Mad Queen. This fortress was once a Cysgor monastery before it was abandoned due to the corruption of the area around it. From here, the Blightguard conduct raids against the surrounding corruption. Despite the name, the people here are as sane as any. The leader changes regularly as souls burn out—the average Blightguard only lasts 1-2 years.
The Departed and Afterlives
All that lived must die. This is a fundamental fact of the Mortal plane. Nothing, once mortal, can be eternal without cost. Loss, forgetting, oblivion are the inescapable fate of those that die and pass into Shadow. Thus, the soul lives out a span, and then "dies" again. This happens in many different ways, but the general term for this second death is dissipation or dissolution. But in what state are they before they dissipate?
The sparks of the dead carry with them the nimbus that once mediated with their physical bodies. Upon arrival in Shadow, this nimbus begins to accrete a body of shadow-stuff. For many, this is an unconscious process that results in a body that matches the soul's self-conception. A few retain enough presence of mind to influence the process. While this accretion process gives them a body with which they can manipulate shadow-stuff and interact physically with visitors and other residents of the plane, this body is both volatile and more limited than the physical body they once inhabited. Severe emotional disturbances, afflictions, or even sensory overstimulation such as sexual climax can disrupt the hold of the nimbus on the shadow body, resulting in leakage and partial dissipation. Predators (sapient or not) can draw off portions of one's "flesh" with a touch. Large influxes of energy (such as a mana geyser in Mirrorhaven) can blast it apart, even though they would only injure a physical body. They are more limited in that they do not have the same capabilities for growth or development, as well as for magical manipulation. Those who were skilled with mortal magic find themselves capable of manipulating shadow stuff as if it were magic, but their magic is only a limited mimicry of their former capabilities. A few individuals avert this and retain much of their power--these individuals often find themselves ascending to the other planes as a result.