While the normal (or shallow) plane of shadow is a reflection of the material world, the deep plane of shadow connects the shadow realms of alternate material planes. According to Lords of Madness, the Grell traveled to our material plane with world spanning gates passing through the plane of shadow. Since then many of these gates through the deep shadow have been kept open, tended to by many Grell. Two of these gates are the ones that connect the prime material plane to the deep shadow, and another which branches the deep shadow to the Grell's alternate material plane. In the middle, a Grell controlled port of sorts has emerged, which the natives call G'llyach. The port allows spelljamming ships, called shadowjammers, to sail through the deep shadow into the space of alternate material planes. The tolls paid to the Grell have made them incredibly wealthy, but the price they demanded is not always monetary.
What terrors and wonders await in the deep plane of shadow?
G'llyach is a city of eternal darkness, which suits the usually sun-hating Grell perfectly. A striking feature of the city is that it appears darker than black. Despite floating in a pitch black void, it is clearly visible, almost radiating an even deeper darkness. It is never day, and the brightest lights are the occasional dim violet glows of the world gates as ships pass through. The Grell float along the jagged structures of the city and vanish into tunnels deep within it. The Grell do not walk, so the city has no streets. From the distance the city appears as a fusion of stones, but it is actually made of shadow stuff, which shifts and moves over the years. Because the city is so dark, a traveler may bump into an alien creature if they are not paying attention.
Artificial lighting is dimmed in G'llyach, and even with a bright lantern a visitor can only see a few feet. In the rare circimstances where things sre illuminated, colors appear bleached. The Grell and other abberations that live in the city seem to get around just fine.
> What terrors and wonders await in the deep plane of shadow?
- Things half created, formed, or mutated that wish never to be seen
- Dark creatures that hate the sun
- Predators who hunt in the dark
- Exiles and prisoners deemed too dangerous to even be on the Material Plane
- Astral aliens
- A crazed celestial that radiates light but is chaotic and overstressed
Those familiar with the Grell know of their strange alchemy, which relies on physics not of our world. In G'llyach, the physics of the Grell's universe bleed in more strongly, allowing construction of bizzare and dangerous artifacts.
>>54210092
>- Dark creatures that hate the sun
You mean...GOTHS!?
>>54211278
Let's run with that idea for a sec
A small group of humans has made the city their home. Years spent in utter darkness has left them with pale skin, and this paleness makes them some of the most visible creatures in the city. Being visible is not an advantage for a defenseless human, and so many of these humans cloak themselves in black clothing and dark makeup to blend in with their surroundings.
An oddity of G'llyach is how the locals keep time. There is not one single clock or calendar, but five (or maybe more) running simultaneously. The passage of time is tracked with alchemical clocks that emit different electric pulses. These pulses can be felt by the Grell's electroperception, and can also be heard as faint buzzing noises. The purposes of most of these clocks are not clearly understood. It is obvious that the shrieking and motions of the locals change accordingly with the clocks, but exactly what this signifies is hard to say. The two clocks that are understood by all are the clock which governs the opening and closing of the gates, and the one that governs feeding. Every so often, the feeding clock buzzes in a way that indicates it is time for a feeding frenzy. Eating is a critical part of many Grell cultures, and the wise hide themselves away during this time.
>>54210092
>- Astral aliens
G'llyach has become a home to many Psurlon, who borrow deep into the shadow stuff of the city. Why so many Psurlon have migrated here from the Astral Plane is not known. Perhaps they are escaping a new enemy, or maybe they are seeking to expand to a new cosmology. It is possible that the ones in the city are remnants of an earlier migration who never left.
>>54211799