Black Nerve

The sky is a dark ocean of fractal whorls, writhing tendrils, and black turbulence. Where there once were volcanoes, spires of iron and copper stab free of the ground and reach for heaven. In place of one moon, there is a dark orb emitting corrupt energy.

There are turbines and fridges available to all save the poorest homes; only, when they break, their fumes can poison entire neighborhoods. A carefully constructed room may have an interior vast as a mansion. In the secret research sites scattered the antartic wastes, percipients grow enormous, lightless unstars that look like holes carved into reality.

Banes can wield the five elements; shadowcallers can level and blight entire towns; scourges can breathe radiation and some have walked through walls. Vindicators can kill all of them.

The answer to how, for all these facts, is the same at the root: umbra.


Enervate — otherwise called black nerve, the essence of umbra, tenebra’s blood, liquid shadow, or soulflesh — is an paraphysical phenomena similar to yet distinct from other forms of energy or matter. The core mechanisms of enervate are simple at a distance and nuanced up close. Put tersely, it absorbs. This means it attenuating energy, this means sucking and engulfing matter, and even distance does not behave the same in the maw of enervate.

But those are causes. What you experience are effects.

Historically, encountering substantial amounts of enervate was first and foremost fatal, but it also tended to be in a particular form: nerve​-​crystals deep underground. If you happened across them, you were probably a hapless spelunker scouting a vast cave. Here’s what you would perceive:

First would be a certain absence. Enervation is notable in that it is, by itself, a vector of erosion, and hence allows forming caves that are dry. Where your journey down from the surface probably followed the path of water weathering rock, the closer you come to veins of nerve​-​crystal, the more you walk on the work of this so​-​called liquid shadow. You’ll see stone that is curiously compacted and textured, as if it melted or burst from pressure; but you’re no where near deep enough for either process to happen naturally.

And then you’ll come upon the crystals themselves. They are invariably tiny things; superheavy umbragenic metals are the rarest substance of all. But liquid shadow has spilled forth from them like from a geyser, and coats the walls and floor.

Then you’ll feel a chill.

Caves, as a rule, have a very consistent temperature, and even a little shift is a shock. The closer you come, the colder it gets. And this is a special kind of cold, which never gets warmer. It’s not a cold that might budge through a process of convection with a hotter body; a mutual equilibrium will never be achieved. The cold of liquid shadow strips away heat, and it does not give it back.

Next, you’ll think your light has gone out.

Caves are very dark places; a few turns deep and there won’t be, can’t be, any third or fourth order reflected light to give you sight. It becomes a darkness to which your eyes will never adjust, only plead for a torch. And, coming upon the nerve​-​crystals, the same principle holds without any alleviation: no matter how close you bring your torch or lamp, no light shined out onto it reflects back to meet you. It is as if the rays die on liquid shadow. It’s vantablack, a darkness described as umbral; the absence of sight, a hole which seems to have no depth, and it seems to draw you inward.

Next, you’ll think your ears have stopped working.

If you’ve gone deep enough to find nerve​-​crystals, there might still be running water flowing down, perhaps dripping off stalagtites to descend with a soft plink into a puddle. You won’t hear this unless you can see it. Liquid shadow does not reflect sound, and close to a nerve​-​crystal it starts to travel like light. Your footsteps stop echoing.

Finally, you’ll smell pain.

The olfactory response of enervate is unlike any other substance. Because liquid shadow is of particular danger to every living organism, the evolved sensors for it are especially acute, and especially hard to ignore. Acids may taste sour, and poisons bitter. But capsaicin is closer comparison, inducing not a taste but a visceral burning sensation. Enervate is distinct from, and worse than, all of them. To those who have never experienced it, it can best be summed up as an odor which hurts, from which you instinctively draw back.

Fittingly, this is actually the only direct perception of enervation you can experience — all the rest are knock​-​on effects, second​-​order phenomena. Liquid shadow’s only phenomenological correlate is aversion and repugnance.

(The oldest wisdoms say it’s like death bearing down you on. Whether that’s describing the smell itself, or the gestalt of all its sensory consequences, it’s hard to say.)


It’s not hard to see what’s happening, all these cases: Enervate attenuates energy. That means light is absorbed, rather than reflected or emitted. That means incident matter is sapped of its kinetic energy; hot air cools, sound is dampened. (Put a pin in smell.)

So, that’s the first aspect down, but what about the second?

Enervation imbues matter. This encompasses two facts: one, enervate and matter upon each other exert a (usually attractive) force; and two, enervate will suffuse matter, subsuming it until its behavior is that of enervate.

The mutual attraction or repulsion between enervate and matter is called induction; enervation is said to induce nearby matter.

Different substances can be imbued by differing amounts of enervate: generally more massive elements allow more enervate to shroud them, and more massive enervates can imbue more matter. The ratio of enervate to matter is called the concentration, with 0:1 concentration of course being perfectly ordinary matter and any ratio higher than 1:1 being completely shrouded matter, which begins to behave largely as ordinary enervate (such as absorbing energy).

In a sense, enervation attenuates the normal force; if you were to imbue a table, it would sink into the floor. If you bring a fluid up to 1:2 saturation, its volume halves.

But this presents a problem. The normal force isn’t primitive. It’s a consequence of electromagnectic repulsion and Pauli exclusion. Couple the observed volume reduction with the effects on enervated bodies once cleansed: they look to be compressed, dissolved. What this suggests is that, in some sense, imbuement allows matter to overlap spatially with other matter.

When abstracted and codified into mathematics, this notion becomes phase theory, which introduces a new physical property: the phase index. Ordinary matter is said to be subject to phase​-​grounding, creating what’s termed the material hyperplane. Enervate intercedes with this grounding, allow phase indices to shift.

To illustrate this, imagine a tub with a thin littering of iron fillings at the bottom, like sand. The tub and the fillings are three dimensional, but in a meaningful sense, they are essentially two​-​dimensional; if you were a little grain of iron, all of your fellow iron fillings would lay on a plain around you. If someone takes the tub and gently rocks it back and forth along the ground, the fillings may bounce into each other, but all will be confined to that plane.

But now tie some magnets to strings, and dangle them over the fillings in the tub. Suddenly some may be drawn upward toward the magnets, along a dimension foreign to them.

The analogy is not perfect, as magnetism and induction are very different phenomena, and the idea of phase indices being spatial, reality having more than three dimensions, is unimaginable — but it provides an intuition for why imbued matter behaves the way it does; matter is confined to the prime material hyperplane, and enervate may lift it.


Enervate does not violate energy conservation. If you shine a light upon a enervate for long enough, the energy those photons embody does not disappear.

Enervation has a property called saturation, which increases for all energy absorbed. Many behaviors of enervation depend on saturation; how much energy is attenuated, how tightly bonded to matter enshrouding enervation is, and what force enervation exerts on other enervation.

These effects can be analogized in several ways; as energetic enervation retreating into its imaginary higher dimension space, thus decreasing the volume which intersects with the material hyperplane and displacing it nearby enervate along a potential gradient. Modulation theory, however, holds that enervate stores a fraction of its energy in a kind internal motion or vibration of component parts. In a weak sense, this would suggest a way to speak of the temperature of an enervate.

As mentioned above, enervate expresses an attraction or repulsion to other enervate depending on its saturation: the rule is the more saturation, the less attraction, until attraction disappears entirely and flips sign, becoming a repulsion. This effect is is called cohesion and repulsion.

Even if two enervates attract, however, they still must occupy volume; this means runaway cohesion does not cause an enervate to shrink down into a black hole, and ultimately this means that enervation has a certain viscosity. Overcoming that results in fusion of lighter, simpler enervate into more complex species.

Each enervate species has a saturation threshold, above which it undergoes fission, decaying or evaporating once more into a lighter, simpler enervate.

Two two facts grant enervation a sort of parachemistry, and allow, through umbrasynthesis, knowledge​-​hunters and vesperbanes to generate endless forms most fascinating.


The Primary Sequence

What follows is a list of the most common, most well​-​studied enervate species.

The primary sequence of enervate (Alpha, Beta, Gamma, Delta) are the four most abundant species. They can be produced one after another in sequence via a simple process of fusion through compression.

Alpha​-​nrv: tiny, non​-​inducing, and incredibly light, alpha​-​nrv is of limited use and is only ever produced by the decay of more complex enervate, and some call it a ‘subprimary’ species for this reason. Others know it as ‘waste enervate’. Because it is so light, and because it is non​-​inducing, alpha​-​nrv is behaves more like light than a substance. Because it experiences cohesion, it can be used to locate nearby enervate. Under pressure, it fuses to form beta​-​nrv.

Beta​-​nrv: light and gaseous, most enervate is beta​-​nrv. The most common metallic nerve​-​crystals yield beta​-​nrv as a neurogenic byproduct. It is lighter than air (comparable to helium) and thus it tends to float up into the atmosphere. A layer of mainly alpha​-​ and beta​-​nrv exists at the top of the atmosphere, called the celestial umbrasphere, and it deflects cosmic enervate flow and attenuates sunlight. This layer is visible as a variable darkening of the sky. Beta​-​nrv has low saturation, and will begin to undergo fission in sunlight or even warm shade, and above about 50C in an oven. It will decay into alpha​-​nrv, but under pressure, it tends to fuse into gamma​-​nrv.

Gamma​-​nrv: massive and voluminous, gamma​-​nrv is the vesperbane’s darling. Unlike beta​-​nrv, gamma’s saturation threshold is high enough to withstand sunlight and room temperature for a time. It may liquify, even sublimate, in these conditions, but outright fission takes a while. And when it does, gamma​-​nrv is theoretically thought to decay to beta​-​nrv, but because beta​-​nrv fissions so much more readily, practically speaking gamma​-​nrv fission results in ephemeral alpha​-​nrv. In many ways, gamma​-​nrv is “beta​-​nrv, but more”; where beta​-​nrv was a light touch, heavy gamma​-​nrv exerts a noticeable force on nearby matter, and quickly brings a chill into any room. At extreme pressures, it can fuse to produce delta​-​nrv, but with current tech this is prohibitively expensive, and thus an academic exercise.

Delta​-​nrv: exponentially more heavy, more expensive and rarer than its precursor, delta​-​nrv is largely a curiosity. Its saturation thresholds are so high, an hour in a furnace would scarely faze even a moderate ingot of it. Delta​-​nrv isn’t attracted toward matter so much as matter is attracted toward it. Exposed to a room, it will quickly suck the argon and oxygen out of the air, and render the choking remains frigid. Delta​-​nrv has been experimentally left heating for days to study its fission behavior; it decays to gamma​-​nrv (as expected) and this gamma​-​nrv is resilient enough to not result in immediate further decay. At least, not immediately enough the results can’t be observed. Theoretically, if only for the sake of science, naïve calculations suggest fusing delta​-​nrv should just barely be within possibility with the current techniques; however, a peculiar phenomena actually renders this a non​-​starter.

The Epsilon Defect; the Process of Amalgamation

For the artificial fusion of alpha​-​, beta​-​, and gamma​-​nrv, we use pistons made of saturated amalgams to subject the enervate to extreme pressures, squeezing them ever closer until they overcome repulsion and fuse. Using saturated amalgams like this means that the compressed enervate will likewise be saturated; but the pressure means that any decay products this generates swiftly fuses back. And when a fraction of the enervate finally does undergoes fusion, further fusion is catalyzed, because the fusion products exert more pressure.

However, Delta​-​nrv is the exception to this rule. Or perhaps it’s the point where hitherto neglected terms in the equation start to matter. Either way, attempting to compress delta​-​nrv in this manner runs aground on what’s called the epsilon defect.

Epsilon​-​nrv: produced by delta​-​nrv under pressure, episilon​-​nrv is a small and reactive species thats breaks all the patterns of the primary sequence. Epsilon is partway between alpha​-​ and beta​-​nrv in mass, but is quite the opposite of alpha: its cohension is weak, but its induction is intense. Between its size and its induction coefficient, the enshrouding behavior of epsilon​-​nrv is unique; it can warp the bounds which bind matter and amalgams, to act as a corrosive agent (what’s called umbralysis, or even eponymous epsilysis), or to insert itself and forge nerve​-​bonds, creating an amalgam.

Like this, epsilon​-​nrv punctuates the primary sequence, and this begins the secondary pathways.

But first, a word about amalgams.

Alpha​-​nrv is aloof and non​-​inducing, and beta​-​nrv is too big and too weakly inducing to do anything but stare needily at atoms from a distance, but epsilon​-​nrv is none of those things. As such, its presence has chemical consequences. The result is referred to as an amalgam, a substance which is neither pure matter nor pure enervate. Phenomena, such as alpha​-​nrv cohesion, which mainly affect enervate still effect amalgams, and phenomena, such as temperature and macrokinetics, which mainly affect matter will still effect amalgams.

Most interestingly, and least understood, is that imbued enervate can be warped by matter in certain amalgams. This allows amalgams to have properties impossible for pure enervate. An example is the “neurophobic” amalgam zeta​-​nrv, which always has negative cohesion, or the “universal repellant” upsilon​-​nrv, which perplexingly has anti​-​induction, and is essential in the construction of parallel spaces.

Zeta​-​nrv: light, weakly inducing, and most importantly, negatively cohesive. Zeta​-​nrv, even when cooled to superlow temperatures, maintains at least a slight repulsion from all enervate. Zeta​-​nrv alone is the keystone which allows enervate engineering to be possible at all. Pure zeta​-​nrv is a gas (toxic, but surprisingly non​-​lethal for an enervate), but it can form compounds which are solid. When, for instance, a bottle is coated with a layer of zeta​-​nrv, it can contain most enervate. Without this, they would be dangerously volatile.

Theta​-​nrv: the opposite of zeta​-​nrv, theta​-​nrv is called a “neurophilic” amalgam. It’s not quite comparable to zeta​-​nrv, as at high temperatures theta​-​nrv’s cohension flips sign as it does in pure enervates. But at room temperature, the cohesion is weak enough to allow “nerve​-​conductors”; theta​-​nrv coated wires which connect two bodies, and suck enervate from the least cohesive body to the most cohesive.

Iota​-​nrv: the product of epsilon fusion, iota​-​nrv is heavier, forms stronger bonds, and its threshold is higher. As it’s more stable in ordinary conditions, the epsilon family of autocatalyzing reactions is often called iota​-​combustion.

Rho​-​nrv: singular among enervates for it’s inverted cohesion response, rho​-​nrv is a distinguished combat enervate. Rho​-​nrv feels ostensible attractive forces from other enervate as repulsion, and vice versa. Yet the forces it exerts are not inverted. This means rho​-​nrv is most stable when it is highly saturated, and disperses when it is desatured. Yet highly saturated rho​-​nrv repels other, non​-​rho enervate. This phenomena is called rho​-​deviance. Additionally, partly because of its high rest saturation, and partly due quirks of its own chemistry, rho​-​nrv is very susceptible to iota​-​combustion.

Tau​-​nrv: known as the most stable enervate, tau​-​nrv fuses into more tau​-​nrv, and fissions into more tau​-​nrv. Tau​-​nrv has the strongest cohesion response of any enervate, binding to its incredibly tightly. So tightly that moderate force pushes the enervate to fuse, release energy that rebounds violently against the impetus. Attempting to rip or pierce tau​-​nrv meets extreme resistance. Even when this is overcome, the energy input required to do so is often enough to oversaturated tau​-​nrv, fission into more tau​-​nrv. Tau​-​nrv is often used to construct impressive defenses, and the so​-​called tau whip.

Upsilon​-​nrv: a complex product of an exacting chain of fusions and reactions and eductions, upsilon​-​nrv is the shining jewel of enervate research, even though it is just barely practical. Upsilon​-​nrv has the unique property of “negative induction”; at any temperature, it repels matter. This has endless applications; perfect vacuums, blades with unparalleled ease at parting matter, the list extends. The most useful by far, and the hardest to understand, is “parallel spaces” which extend extradimensionally and without a lethel suffusion of enervation. See Applications: Augmented Space for details. Upsilon​-​nrv is particularly confusing to behold, as at fringes light itself is repeled, bending around upsilon​-​nrv, and making it appear significantly smaller than it is.

Chi​-​nrv: a highly dense store of energy, chi​-​nrv is a key component of red fat, and a sort of energy currency for the vespers, not unlike the ATP molecule. Secular production of chi​-​nrv is thought impossible, only derivable through the complex extended metabolism of vespers.

Psi​-​nrv: a class of so​-​called umbraneurotransmitters, known to have complex interactions with neural tissue.

Omega​-​nrv: calculations based on the leading theories of nerve​-​physics suggest deep inside Tenebra lies a hard core made up of an enervate species significantly more dense than delta​-​nrv ever could be. Dubbed ‘omega​-​nrv’, but never observed, it’s believed to be the true product of delta​-​nrv fusion, and achievable if and when the epsilon defect is ever overcome.

(This document does not, and should not, discuss the myths of “mu​-​nrv” or “lamba​-​nrv”.)

Nerve​-​spires

Naturally, due to their density, most terrestrial nerve​-​crystals lay deep in the planet’s core. But it’s hot down there, and intensely high pressure, so anthropically all core enervate must either fuse and amalgamate into forms tolerant of the core conditions, or quickly flee to the more hospitable mantle and crust.

The places where tectonic activity has unearthed and cooled nerve​-​crystals deposits is where this surface​-​seeking enervate most naturally congregates, a sort of trap or net which keeps them bound to the planet. Denser metals like iron or gold can also serve as weaker enervate traps.

But any enervate that, despite the odds, manages to breech the surface inevitably feels the upward pull of Tenebra and the celestial umbraphere. It will be pulled up, and any matter it enshrouds is pulled likewise. Over geological timescales, and especially if the enshrouded material is the molten metal of a volcano, this upward pull shapes the land into skyward spires. On dark days when Tenebra is full and the neurosphere is black with fresh enervate, you can see tiny streams and filaments of enervate that are drawn up from the earth to join the sky.

Black Latern Diviners

Make a sealed container with insides coated in neurophobic zeta​-​nrv, except for a single spot without it. Fill this compartment with beta​-​nrv. Opposite the hole, there should be another compartment, designed like an latern or small oven. It should allow a flame to be lit and maintained inside, and as much heat as possible should be conducted to the other, beta​-​nrv​-​suffused compartment.

Designed correctly, this device should cause the beta​-​nrv in the first compartment to fission and produce alpha​-​nrv. The neurophic walls will focus the increasing amount of alpha​-​nrv toward the non​-​coated spot.

The result should be a steady beam of alpha​-​nrv, focused to as small a spot as you desire. The beam will be visible as a darkening of the air, and will bend toward nearby enervate sources. This can be used by surveyors to find nerve​-​crystal mines.

[What would a better design be? In this version, won’t both alpha​-​ and beta​-​nrv be expelled from the spot?]

Parallel Spaces; Augmented Volumes

Take a volume of matter, and surround it with saturated upsilon​-​nrv. Enough pressure and saturation will cause the upsilon​-​nrv’s anti​-​inductive force to overcome phase grounding, and the matter will be forced in a metaphorical direction we will call anaward, as if perpendicular to all three conventional spatial axes. It will appear as if it’s been absorbed or crushed by the upsilon.

Done naively, the above procedure would cause the matter to “roll over” the upsilon​-​nrv and the “hyper​-​hill” of potential energy they form, and seemingly spontaneously appear outside of it. (This would cause quite a bit of damaged to the material, as it will now be thoroughly filled with air. If the matter was living, it is now dead.) However, if the inward faces of the upsilon are diluted with some other enervate, it’s possible to create a sort of divot in which the matter can rest, a local minimum to thwart hypergravity.

With enough force, objects can be pushed toward the upsilon​-​nrv. This requires overcoming both the repulsion of upsilon, and the effective force of phase grounding, but with enough precision the the object will “pop” anaward. This can be made easier by constructing a “ramp” of slowly increasing upsilon​-​nrv density.

Altogether, it’s possible to engineer a building with a dimensionally slanted corridor, which may lead to a room you’d naively expect to be on top of or inside of another room, but instead it is fourthward of the room. This is called a parallel space.

Such constructions are tricky, but if one instead uses carefully upsilon​-​nrv to “bend” the space, you can create mere augmented volumes, bigger inside than out, which are more reliable and less confusing than overlaying rooms.