Dreamspace
'Dreamspace is a term for the vastness between the rews of Charos. (To the inhabitants of those rews, it is often called just "space", much like the intermundial spaces of other universes.) The rews are gigameters apart, and dreamspace is unfathomably large—just how large is impossible to say, since it's not known whether or not Charos is finite.
Definition
As is common for intermundial spaces, the exact definition and delimitation of dreamspace are somewhat subjective. An inhabitant of an isolated rew with little traffic or contact with other rews might consider dreamspace to encompass all of Charos aside from that one rew, including other populated rews of which that individual may know little or nothing. To those of worlds where other rews are better known, and certainly to cosmologists, dreamspace may be taken to exclude all inhabited rews. Even then, though, views may differ on whether uninhabited rews are included in dreamspace or not—to a cosmologist, the answer is generally no, but to a layman generally yes.
Even more contentious is the question of just where above a rew dreamspace begins. Certainly few would place the boundary of dreamspace at the very edge of the rew's atmosphere, where the air gives way to the spacemist; that verge is the dreamsea, and has features and ecosystems of its own that extend some distance into the dreamspace itself. But there is no consensus as to just where the dreamsea ends and dreamspace begins. At one extreme, some hold the dreamsea to include only that part of dreamspace visible from the surface, which would make it only a few meters deep. At the other, some look to the creatures that frequent the atmosphere's margin but spend much of their time in the spacemists beyond, and take the dreamsea to extend as far as these creatures are found, which may be several kilometers from the surface. Of course, the question is ultimately a semantic one with little practical importance, and even most people who travel the dreamseas don't bother trying to define precisely where it ends. In any case, certainly anything beyond a few kilometers past the atmospheric boundary is unquestionably part of dreamspace, even if some nearer regions are iffier.
Contents
While those living on the rews of Charos may think of dreamspace as just an empty expanse, this is far from the case. It is more a plenum than a vacuum, filled with the tenuous but not entirely matterless spacemists. The spacemists come in a variety of colors, and while transparent, they are not entirely pellucid; visibility through the mists extends a few kilometers at best, and much more frequently is only a few meters. Nor are the mists always still; while in most areas of dreamspace they are motionless, or drift very slowly and apparently randomly, there are sparse networks of swift-moving "rivers" of mist called fleams and occasional vortices called swelgers, and there are certain features near which the mists move in slow but regular patterns.
Not as pervasive as the spacemists but appearing in all parts of dreamspace are the features that gives dreamspace its common name: dreamscapes, transitory collections of scenery and objects, small-scale inscenations on which strange and shifting scenarios play out. These short-lived scenes flicker haphazardly into existence in random locations, and then flicker back out again just as abruptly. They are called dreamscapes not just because they are dreamlike in their phantasmagoricality, but because they are commonly believed—not only by the general public, but by many scholars as well—to literally be the embodied dreams of distant sleepers, either in far parts of Charos or perhaps in other estures altogether. Dreamscapes seldom last more than an hour or two and are sparsely spaced enough in seldom-traveled dreamspace that people rarely find themselves within one unless they go out of their way to do so. However, very occasionally when a dreamscape disappears some element remains and lingers. If not somehow found, these dream remnants may float indefinitely unseen in space.
By far the largest apneumatic objects in dreamspace, in length if not necessarily in volume or mass, are the skyfalls, great cataracts plummeting off the edges of rews, eventually to impinge onto other rews far below. The skyfalls of course descend in the gravitational direction of the rew they originate from, and therefore the vast majority of skyfalls fall along one of the three canonical axes, forming an irregular three-dimensional lattice of falling fluids. Skyfalls of other orientations do exist, falling from diagonal rews, but these are even rarer than the diagonal rews themselves, since most such rews do not have a ready source of water falling on them to replenish what would be lost to the falls. The vast majority of skyfalls are composed of water, with dissolved salts and other minerals, but a few falls are known of more unusual substances, including oil, alcohol, quicksilver, and soralia.
There are other features sometimes found in deep dreamspace, though they are little studied and poorly understood. Sometimes bits of spacemist spontaneously solidify, for reasons that have not been convincingly explained, and apparently catalyze further solidification, forming a fractal mass called a crystal reef. In other areas, the mist undergoes a similar process but instead of fully hardening instead semisolidifies into a jellylike mass of glowing substance called a celestine. In yet other places, giant spheres of air called bells form far from any rew. Also occurring in dreamspace are clouds of dust called nebulas and regions called argustines where space itself is stretched and distorted.
Life
Although most of the life in Charos lives on or in its rews, and most of the remainder lives on the surface of the dreamseas, dreamspace is not entirely devoid of denizens. Many species are found only in certain parts of dreamspace, but there are a few creatures that have become widespread throughout much of the universe. Naturally, away from the rews, most creatures of dreamspace will be weightless, the better to maneuver freely in space without anything they need to orient themselves to. Next to the immediate environs of the rews, the place in dreamspace where life is most plentiful is near the skyfalls. Not only is there food here in the form of organic matter from the rew where the fall originates, but, obviously, water, and also energy, in the form of the kinetic energy of the falling water. Some of the best known creatures of the skyfalls are linfish, ghostbells, and whirljacks.
In the misty immensity far from the rews and skyfalls, alimentation is much more difficult to come by. The spacemists themselves are nutritively valueless, requiring more energy to convert them to some other form of matter than could be extracted from them. Still, even here there are scattered creatures that have found ways to sustain themselves. The largest widespread life forms of dreamspace are the scusog, the abilute, and the tashmore. The scusog subsists on materials gathered through portals and crepatures to other planes, the abilute by magically enticing what few other creatures exist in dreamspace to approach it so it can prey on them. As for the tashmore, it is undead and so does not require the same sustenance as living things, although much about the tashmore remains an enigma, including the reason for its presence in dreamspace. Smaller creatures found across large parts of dreamspace include the dreamwraith, the landari, and the balebug.
Many celemologists hypothesize that some yet undetected form of life exists in dreamspace, more numerous than the known spacegoing creatures but undetectable, or at least heretofore undetected, by currently available means. This "dark life" is conjected in order to explain how the spacemists change color in the depths of space far from any populated rew, if that change relies on the thoughts of conscious creatures. However, there are many different contradictory proposals as to what dark life may entail and why it has not been detected, and not all celemologists consider it a necessary or useful supposition, some postulating other possible explanations for the phenomena in question and others preferring to accept them as currently unexplained.
Travel
Relatively few people travel through dreamspace directly. Those who voyage between rews more typically do so by sailing the dreamseas, passing from one world to another through knysts and rimgates. Still, some do find a reason to voyage through the void between the rews—to get to worlds reachable by no other known route, or to explore space itself, or simply because they can.
Certainly few creatures native to the rews could traverse dreamspace of their own volition—even those with the power of flight would tire long before they reached a destination so unimaginably far away. But spacefaring ships have been constructed capable of making the journey, in all sorts of sizes, from small spaceskiffs that only hold a handful of people to great spacegoing galleys the size of a large city. Those who actually embark upon such passances are few, and on most worlds traveling through space is a thing unheard of—but, on the other hand, there are some few advanced worlds where it's been so long practiced that it's now considered fairly routine.