A Complete Guide to the Cosmos - Normal and Nightmare
by Giulio CarolettiWe have now discussed and analysed the structure of the Normal Tetraspace, a four-dimensional space made of the Prime Material Planes, the Ethereal, the Elemental Planes, the Energy Planes, the Astral Corridors, the Ensemble of Outer Planes.
However, the whole Cosmos, like we are going to call the whole union of all universes internal to the Vortex, doesn't end here. We still need to discuss the nature of what I will call the Mirror Tetraspace, and is normally known as Nightmare Dimension.
Let's take our normal four-dimensional space, and let's put it in front of a mirror. On the other side of the mirror, there isn't a specular image; instead, there is another four-dimensional space, this time a single one (a single plumcake, ok?), chaotic and blurred, as if the mirror instead of reflecting the single parts of the Normal Tetraspace took all its ingredients, meddled them and then showed them confused and mixed one with the other - after having reverted them completely (sort of left-right, like our commonly used mirrors do). This is the Nightmare Dimension, or Mirror Tetraspace.
The Normal Tetraspace is made up of dimensions 1-2-3-4. The Mirror Tetraspace is made up of dimensions 2-3-4-5. They share three dimensions, but they have a fourth each different from the other. So the Cosmos inside the Vortex results being a pentaspace, a five-dimensional space.
All normal mortal creatures are four-dimensional beings, either Normal (1 to 4) or Nightmare ones (2 to 5). They perceive themselves as three-dimensional creatures, the Normal as 1-2-3 dimensional creatures, the Nightmare as 3-4-5 dimensional creatures. The fourth dimension can be perceived only partly. The ability and skill to perceive and draw upon this fourth dimension is the ability to use magic; like any other ability, the mastery of magic can be learned, although there is always a natural predisposition to it, in a way similar to playing an instrument, learning higher mathematics and so on.
Creatures of Immortal level, like True Gods and Immortals, can perceive all four the dimensions of the Tetraspace, and this is the main reason behind their immense powers.
To cross from the Normal to the Mirror Tetraspace, a creature must undergo a process of "reversion" that converts its 1st dimension into the 5th, its 2nd into the 4th, and its 4th into the 2nd or vice versa, while the 3rd dimension remains the same. This process may take place through spells or through magical gates that leads to a corresponding point in the Mirror Tetraspace. There are also magical mirrors that show what lies on the "other side" in the Mirror Tetraspace (or, if you are already there, in the Normal Tetraspace), and they are sought by any mortal that would dare trying to pass to the other side...