In the beginning of the Cosmos the Universe inflated and expanded forth from the quantum Chaos. Quantum
fluctuations froze out in disequilibrium and inevitably, and yet against the odds, order arose from the chaos of
fluctuating vacuum quanta. In this early phase, the Planck era and shortly thereafter, there were more
dimensions than those now familiar to us, but some were unstable and so collapsed or compacted into 'shells'
which curved in upon themselves in infinite recursion. Filling the vacuum of space, present at every point and
as every point in the graininess of the space-time matrix, these shells contain immense energies and vibrations
locked-up in hidden worlds which are normally only accessible with the aid of immense energies. Curiously,
consciousness resides partly in these hidden worlds and the beings of these worlds are sometimes able to
contact the receptive and sensitive, or perhaps unshielded, mind. So they can speak to us in dreams and
Terra Arcana, the Mystic Earth or Midgarth, inhabits a region of space where things are subtly different. Here
the laws of physics manifest in different forms, perhaps due to some spatial variation in the natural laws across
the vastness of space and time, or perhaps because of the peculiar dimensional geometry, perhaps a knot in
space-time, or some curious resonance in the energies of vibration of the various hyperplanes. Whatever the
cause, here the veil between worlds is more easily breached and beings from the Shell Dimensions have been
known to manifest in more substantial forms. Sometimes a rift or tear spontaneously appears in the cosmic
matrix, sometimes they are recklessly summoned forth by means of complex formulas and equations, written in
languages understood by few, supplemented by mysterious ancient artifacts and psychic or astral vibrations,
all of which serve to facilitate the opening of portals to the other dimensions.
Among the most alien and toxic forms brought forth are the Shell Demons. Beings whose mere presence
poisons life as we know it. Be they truly evil or not is a matter of conjecture, but they certainly have intelligent
designs of their own which have conflicted with those of civilisations native to Terra Arcana. The unusual
properties and abilities of the more powerful known classes of these beings, the Shell Lords, has caused them
to be worshipped as gods by some of the more superstitious. Their appearance is totally alien. Writhing
masses of tentacles, pulsing and writhing to peculiar rhythms. Their languages, science and arts are
mysterious but clearly super-advanced. The worlds where they naturally dwell are very different to our
spherical orbs, with very different physics. Their worlds are hyperplanes wrapped around convoluted
multi-dimensional tori whose geometry defies human imagination. Some are energy-drainers that feed upon
the energies of ordinary life-forms.
Fortunately, they are unstable outside the Shell Kingdoms, though undoubtedly they strive to overcome these
limitations. Shell Demons are a grave cause for concern among the scholarly elite and university conferences
have pooled knowledge on how to banish and contain these beings and to safe-guard the portals betwixt the
worlds. Who can see what future moves will be played by these dreadful beings?