Tsithca'ca'dss, the Trench Dwellers

In the deepest of seas, far below the sun-brightened waters of the continental shelves, lingers the remnant of a once-mighty empire. Long before the coming of the wise and cruel meremenne, before even the madness-worshipping Batrakhones were found in the seas, the Tsithca'ca'dss, the 'Trench Dwellers', crafted labyrinthine cities and incomprehensible citadels miles below the ocean's surface. Many of their ancient cities have vanished, lost below the silt of thousands of years, but a handful of sites remain. Within these lightless metropoli, the forgotten lords of the deepest seas live on, their tripartite minds lost in contemplations too alien for human understanding.

Description
The Tsithca'ca'dss are a physically small species, most closely resembling a spined trilobite or horseshoe crab. Growing to approximately two to three feet in length, they have intricately articulated shells with several small spines growing from each of the thoracic segments. The underside of each segment has small clawed limbs; the front pairs capable of quite fine manipulation. Their mandibles, hidden beneath the carapace, are also used for grasping or shaping objects.

The heads of the creatures have several feathery growths that protrude from small orifices in the shell. These 'feathers' tremendously improve the Trench Dwellers' ability to hear. Delicate sensory organs, the 'feathers' are necessary for the creature to communicate effectively with the others in its triad (see below), but can be withdrawn into the shell instantly if the creature feels threatened.

Tsithca'ca'dss are totally blind, depending on highly developed hearing and an acute sense of smell to perceive the undersea world around them. Each Tsithca'ca'dss constantly emits a soft susurrus of sound, clicking and sighing from a highly-developed vocal organ just above the mouthparts. Their hearing is acute enough that they are able to precisely locate objects near them, displaying a bat-like sonar sense. Because of their vocal abilities and acute hearing, they are often able to communicate verbally with other species, but find doing so very unpleasant. The random sounds and movements given off by other creatures drive Tsithca'ca'dss to distraction, and few are able to share an area with other races for long without being driven to fury by their annoying noises. The noise generated by others of their kind is often comforting to them, so they prefer to congregate in large numbers.

Because of their sensitivity to sound, the Trench Dwellers eliminate any random, uncontrolled noise from their environment. While their cities are filled with items that emit various incomprehensible sounds, each is carefully designed and placed to shape its acoustical properties. The few remaining war machines of the Tsithca'ca'dss are eerily silent as they move through the water, and their functioning organic devices only emit sound if they were designed to do so.

The Triad Minds
Tsithca'ca'dss are unique among races in having a tripartate group mind. Triads of these strange intelligences bond together soon after hatching, remaining together mentally through the creatures' lifespan. Their shared thoughts are communicated through sound, with each triad member adopting a different portion of the collective creature's personality and memories. While they are capable of reasoning independently if separated, they strongly prefer to remain within a few feet of each other. The strange noises constantly emitted by these creatures are 'thoughts' being shared between triad members. This is one of the other reasons why Trench Dwellers find random sounds disturbing; the noises interfere with their ability to 'think' at each other, causing serious discomfort. The presence of others of their kind does not have this unfortunate effect; instead, they often find such company comforting.

If one of the triad is destroyed, its two mind-partners generally pine away soon afterward. These damaged triads often display reckless and insane behavior while wasting away, so damaged triads are often destroyed to prevent them from disturbing or injuring those near them.

Trench Dwellers apparently cease aging once they reach maturity (a process that requires only a few years). They remain physically the same, but as they accumulate memories, they undergo a gradual process of mental confusion. Over the course of hundreds or even thousands of years, they become more and more introspective and uncaring. Eventually they become virtually cataleptic, unwilling to move even to feed themselves or react to stimuli. These dormant organisms can survive for hundreds of years, their minimal food requirements taken care of by autonomic processes that filter nutrients from the water around them. As long as they are not buried in silt or debris from their decaying cities, these torpid dreamers seem to linger indefinitely.

In the surviving citadels and outposts of the Trench Dwellers, vast galleries of dormant Tsithca'ca'dss can be found, shepherded carefully by 'Acanthids', spiny, biomechanical guardians they devised thousands of years ago, when their empire flourished in the unseen depths. These massive constructs are not only formidable battle machines, they are able to release a potent chemical stimulant into the water, one able to awaken even the most jaded dreamers from their catalepsy. The awakened creatures are often very angry, so the defensive machines will only disturb them if their dim mechorganic minds determine that the dreamers face imminent danger.

'Content Sounds': The Society of the Trench Dwellers
When their hidden empires flourished, Tsithca'ca'dss had an extremely convoluted social structure, dominated alternately by the technical and philosophical castes. It was in this period that the Trench Dwellers' cities were constructed, vast monuments to the technical abilities of the race. In a sort of racial 'conspicuous consumption', they built cyclopean halls and tunnels and filled these with intricate machines designed to make them ideally comfortable for their strange inhabitants.

A species with dozens of overlapping technical, philosophical and laboring castes, the Trench Dwellers seldom had social systems that surface dwellers would understand: One moment, the leadership of their people might devolve upon the youngest members of the warlike Militant Philosophic caste, then without apparent reason, more sedate members of the Chamber Builders caste would be in command. These changes were communicated through sound cues incomprehensible to other races, as the background noise of 'content' Trench Dwellers would empower one set of leaders, while 'angry' noise or 'frustrated' noise would cause others to assume leadership.

Since the decline of their civilization, the remaining Trench Dwellers have a wide variety of social patterns, most of which are incomprehensible to other species. Cities and colonies that retain few active Tsithca'ca'dss often have simple hierarchical structures dominated by the Shelter Shaper caste. The top social priority of these creatures is the protection of their colony's dormant members; they will support extensive defensive measures intended to ensure that dormant Trench Dwellers are not molested.

The handful of colonies that have fewer dormant members may display a more vigorous approach, developing trade with the less advanced races nearer the surface. Most of these colonies have been decimated by disease or mishap, and require materials and assistance to restore their ancient equilibrium.

Appetites of the Trench Dwellers
Trench Dwellers are hardy little creatures, able to survive both the frigid temperatures of the ocean's depths and the brutal conditions near the sea floor's volcanic vents. Omnivorous scavengers, they can subsist on a wide variety of foodstuffs. Given their choice, their normal diet is made up of D'ca'kh'he, a variety of sponge-like undersea fungus that grows well in the depths they prefer. They supplement this with any plant or animal matter that becomes available. While they are not averse to devouring the remains of other sentient life, they do not seek out such food.

In addition to their regular diet, the Tsithca'ca'dss retain vestigial organs for 'filter feeding' on plankton or similar aquatic microorganisms. While they are able to subsist on this meager diet indefinitely, this ordinarily provides only enough nourishment for them to remain in a torpid, inactive state. Active Trench Dwellers require a more varied diet to maintain their health.

The Trench Dwellers' 'Farms'
In some areas, Tsithca'ca'dss established vast undersea 'farms', where they cultivated animals and plants suited to the depth of the farm. Farms in the black depths would yield large amounts of the slimy D'ca'kh'he fungus, while those in more shallow waters might cultivate plants. Trench Dweller farms near the surface were normally tended by bizarre insectiod biomechanisms, in order to minimize the number of Trench Dwellers forced to dwell near the surface. Since the decline of the Trench Dwellers' culture, most of their farms in shallow depths have been abandoned, while others have been taken over by other aquatic races. These creatures often give tribute to the unseen dwellers in the depths, dumping large amounts of food and usable waste into the trenches in exchange for the assistance of those ancient cultivation biomechanisms that remain. This system generally benefits both species, as the Tsithca'ca'dss are able to use many materials that other species would regard as waste. What they can't eat themselves goes to fertilize their fungal fields.

Treasures of the Tsithca'ca'dss
While the Trench Dellers are a withdrawn race, often avoiding contact with other species, they are not always opposed to occasional trade. The unaging Tsithca'ca'dss often overtax the resources of their native trenches and are forced to gather foodstuffs from shallower regions. While they prefer to do this via 'farms' maintained by their strange biological automatons, they have sometimes established regular exchanges of metal tools or other items of their strange technology for food and fertile wastes.

The unusual bronze-like alloys of the Trench Dwellers are generally very durable, although they can prove brittle. Resistant to corrosion in ocean waters, they eventually discolor to a greenish tinge. Although they are resistant to damage, they are not indestructable; misuse will break them in short order. Surprisingly, ingestion of the filings produced when sharpening these tools can produce illness or even death: The metal is quite toxic.

More conventional metals are also used by the Tsithca'ca'dss. They are sometimes known to craft jewelry or other items from gold or platinum. These items are invariably made for other species, as they do not value jewelry for its appearance. Trench dwellers do occasionally adorn themselves with intricately crafted items; to surface dwellers, these could be described as intricate noisemakers made of material that resembles nothing more than hardened bird droppings. What the Tsithca'ca'dss find appealing in these items is another mystery of the race.

The Trench Dwellers mastered numerous unique technologies in their heyday, many having to do with the manipulation of sound. Other items crafted by these odd creatures included many devices designed to manipulate their environment, controlling the temperature, mineral content, and even pressure of the water in the ocean's depths. Brought nearer the surface, many of these devices operate erratically, if at all. One disturbing capability of the trench dwellers was the technology to alter the creatures around them. An example of one of these unnerving devices was a strange sheet of material resembling fungus-infected kelp, that when wrapped around a surface dweller would cling tightly and alter them over the course of several days to be well-adapted to the crushing depths of the ocean.

Trench Dwellers in the Campaign
How can these strange undersea dwellers be used within a game? If you're running an undersea fantasy game, they may come into conflict with the races dwelling on the continental shelves, who may be unprepared to descend into the midnight blackness of the depths. Surface dwellers may also find their ships attacked by the war machines of the Trench Dwellers, if their fishing disrupts the farms of this alien species.

Geological or magical disasters may force the Trench Dwellers to the surface, as their beloved cities in the depths are overcome by volcanic activity or destroyed by undersea earthquake. Colonies of these strange insectiods may appear at the shoreline, begging for refuge in human-held waters after their ancient homeland is lost.

More often, the Trench Dwellers themselves will be a mysterious race remaining in the shadows, occasionally appearing as the source for strange technological or magical objects in the hands of other races. Ruins of their ancient cities will surface after great catalysms, their odd machines will sputter to life when dragged ashore in fishermen's nets, or they will be described as the legendary destroyers of other ancient peoples.

In a Futuristic Science-Fiction setting, they may appear as the hidden race dominating some watery world, that must be treated with to acquire their jealously guarded resources. They may even appear in a modern-day game, as a hidden race responsible for the legendary technologies of places like Atlantis.