The Abyss

The “great out there”. Space. The Abyss is a bottomless, surfaceless and water-filled void that surrounds Dunia. While exploration of the Abyss is only in its infancy, scientists are already convinced that the void has no end. No matter which direction you travel, you will never reach an end. It is the infinity beyond the world-dome.

People have known for centuries that the world is flat and covered by an energy dome that keeps the Abyss out. It is this construct that inspired the development of the domed megacities. The Abyss Gate technology is a result of studies involving the dome and its particular energy type.

Abyss gate

Abyss Gate by Yann Souetre

The Abyss Gate is a huge, circular airlock coupled to a supersized subharmonic resonator. Once the airlock is sealed and the submarine vessel is suspended in place, the resonator activates and slowly phase-shifts the part of the dome that is inside the airlock's circumference. This lets abyssian water seep through the dome and fill the airlock. Once the airlock is filled, the passage into the Abyss is open and the submarine can leave. The gate is located to the east-northeast at enough distance from the periapsis of the sun to allow for safe operation.

Abyss Gate by Yann Souetre

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Outside the World Dome
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The Arcom Nixie is a popular personnel and cargo carrier for use in the Abyss.

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HyperSonar is a data-transfer technology that uses hyper-focused rays of soundwaves to transmit data across great distances in dense mediums, like the waters of the Abyss.

Geographic Location | Jan 21, 2021

Islets, also called "Death Pebbles", are small floating islands that are found in dense clusters in the Abyss. While rich in minerals and chemicals, they pose a significant navigation hazard to submarines. Particularly in areas near volcanic currents.


The Abyss does not have gravity and most submarines built for Abyss exploration are built with this in mind. The Abyss is mostly empty "water". The abyssian waters exhibit different properties than Dunian water.

Abyssian Water

One does not go swimming in the Abyss and live to tell the tale. While the Abyss, peculiarly, have little water pressure (equivalent to about 15-20 meters depth throughout, with slightly higher pressure near large islands), it is freezing. Depending on location, temperatures range from -5 to -60 degrees, yet the abyssian water doesn’t freeze solid unless it comes into contact with air and settles. Horror stories of colonies that have experienced a breach tell of people freezing to death in icy water that solidifies as soon as it comes to rest, turning the base into an eerie tomb enclosed in ice.

Abyssian water has a teal tint and a weak bitter taste. It lacks all the beneficial minerals and nutrients that Dunian water has and while it can be drunk, it does more harm than good. With its lack of beneficial chemicals, it will pull nutrients, salt and minerals out of the body through osmosis, leaving it in a dangerously unbalanced state. It contains a plethora of foreign substances, likely from abyssian volcano eruptions, that can be harmful to ingest.

In some locations on certain floating islands, heavy volcanic activity heats the water to high temperatures instead, causing strong currents when the hot and cold waters meet.

No bottom or surface has been found in the Abyss and the lack of an increasing pressure shows that the Abyss lacks gravity to compress the water. There are currents and bubbles left in the water drift with the currents rather than rising towards a surface. The bubbles will eventually destabilise and dilute with the water.

The Drifting Islands

Free-floating islands similar to Dunia exist, but so far no islands as large have been found, and no other island have had a dome covering it, ruling out the chances for any land-based life.

These floating islands are often rich in rare resources and several corporations have begun prospecting and establishing mining bases throughout the Abyss. These islands appear to all have the same gravity as the world, pointing roughly perpendicular to the island's surface, giving the Abyss an absolute horizontal plane of reference, but with the lack of gravity away from the islands, maintaining this orientation becomes difficult.

The vast majority of floating islands are very small, barely larger than a few kilometers across. These small islands are called islets, colloquially called "Death Pebbles" because of the significant navigation hazard they present.

Worse yet, science has discovered that the floating islands that dot the Abyss are all free-floating in the inky blackness, which means they will drift with currents and change location. On the macro scale, these movements are perhaps small, but they are enough to put colonies in danger of drifting out of supply and communication range. Worse yet; the constitute a fatal navigation challenge for those traversing the Abyss.

Lost Colonies

Colonisation and exploitation of the Abyss has been ongoing for almost two centuries with hundreds of established colonies throughout the ever-expanding influence of Dunia in the Abyss. However, with The Cataclysm, the vast majority of governments and corporations managing these colonies were destroyed. Suddenly without either communication with or supplies from Dunia they found themselves isolated and left to survive on their own.

With locations of colonies being a closely guarded secret among corporations, there was no way for the reeling survivors in Fusion City to even begin thinking of saving these colonists. It is believed that the vast majority of established outposts and colonies died out within seven months to a year following the Cataclysm, due to lack of supplies and maintenance. Some may have miraculously survived through ingenuity and design, but especially the older outposts were not designed to survive in isolation and lacked the ability to generate oxygen, food and drinkable water in suffifient quantities to survive for too long without relief.

Those who are most likely to have survived are the new experimental colonies that were built to be self-sustained colonies in the dark reaches of the Abyss, like New Gailo. The rest are likely lost in the darkness forever, having drifted far out of supply and communication range and lacking food and water, making them dark, deserted tombs.

Traversing the Abyss

With its extreme cold, pitch blackness and great distances, travel in the Abyss is difficult and dangerous. There is no all encompassing GPS system, no permanent landmarks or lights to guide you. Just knowing what is the universal "up" and "down" is a challenge when you're lost in the inky blackness of the Abyss.

Inertial Navigation

Ships, airplanes and submarines have navigated Dunia with the help of Inertial Navigation Systems [INS] for more than three centuries. INS are dead-reckoning systems that use information from previous determined locations, inputs from gyroscopes and accelerometers and complex computers to calculate where you are. Using the sensors to track in which direction you have moved and for how long, you can calculate with decent accuracy where you are.

Dead-reckoning systems are plagued by cumulative errors as there is no way for the system to self-correct. With the relatively small distances traveling across Dunia, INS have been accurate enough to get anyone wherever they need to go safely. Especially with direct communication of land-based navigation stations helping to realign INS on the fly.

Circumventing Unreliability

Unfortunately, INS are too unreliable to function over abyssian distances due to the cumulative error margin and in order to remain safe, they must frequently be realigned. This puts a hazy, but ultimately absolute, limit on how far you can travel with INS. While most manufacturers recommend a realign every 6 to 12 hours, you can technically go for 12-20 hours and still be reasonably accurate within a kilometer of your destination. But when it comes to narrowly navigating a debris-field or an islet cluster, you need more accuracy than that.

Many vessels have been lost due to navigation errors, crashing into an islet or getting lost in the darkness. Even when stretching the reliability of INS, you wouldn't get anywhere in the Abyss due to the extreme distances.

The Bouy Network

To combat the inherent limitation of the INS technology, the Abyssian Bouy Network was invented. The ABN is a series of sophisticated and expensive probes that interconnect to each other via Hypersonar and use their relative locations to adjust their position in the Abyss and remain stationary relative to Dunia. Vessels can approach these bouys and realign their INS with the position reported by the bouy and thus extend their operational distance. The ABN also allows communication requests to be sent and received while linked to a bouy. A submarine vessel's own hypersonar transmitters are far too weak to bridge the immense vastness of the Abyss and must use the ABN for relaying messages to Dunia, colonies or other vessels. Without the ABN, a submarine is blind, deaf and lost within a day.

This makes the Bouy network a sort of creeping boundary for Abyss travel, stretching ever further into the blackness like narrow highways into the unknown.

High Frequency Mapping

To avoid crashing into other vessels, islets and other floating debris, abyssian vessels are equipped not only with strong passive and active SONAR but also a high-resolution, high-frequency sonar that uses ultrasound frequencies to build a coarse image from the reflected sound waves. HFS or HF SONAR is used primarily in dense islet clusters and other areas where collision is a risk.

The HFS is commonly linked to the navigation computer to provide either course correction or alerting the subnaut of impending collision. On more modern or more expensive vessels, the on-board computer can display the surrounding geography as a 3D hologram image, giving the subnauts unparallelled spatial awareness of their surroundings.


There appears to be plenty of flora living in the Abyss, but so far, explorers have encountered minimal animal life. There are microscopic plankton living in the waters and the occasional jellyfish-like creatures that float about, but they tend to stick close to floating islands with volcanic activity, where the waters are warmer. In the deep, inky blackness there have been no reports of any lifeforms.

There are of course rumours and stories of colossal monstrosities floating through the depths, but aside from a number of hard-to-interpret SONAR logs, there have been no substantial evidence of such things. In most cases, the logs have been easily dismissed as detected landmasses, rather than anything living. But the rumours persist and the prospect of enormous aquatic monsters make for great storytelling, and entertainment industry in Fusion City have gone absolutely wild with it.

Articles under The Abyss


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22 Apr, 2019 17:11

so was the forcefield around the world created by some ancient civilization? Is the water drinkable? a few residents of the wasteland would probably appreciate that if they lived near an airlock.

22 Apr, 2019 18:25

The dome was put in place by whatever creator there were. Not some ancient civilisation. The world was made that way.   The water is not drinkable right out of the bat, but it can be filtered and refined. The Abyss Gates are however far too large to be used just to filter water. :)

Author of prize-winning RPG settings Dark Shadows and Cinders of the Cataclysm. Designer of the narratively focused CD10.
5 Jun, 2019 23:09

This is absolutely one of the more horrifying replacements for space I've seen in a setting. I've seen flatworlds in WA, and firmament worlds, but this takes the cake as the sort which invokes utter terror in the concept.   I dislike open water, but at least even in water bubbles help to orient you so you can swim to safety. Not in the Abyss. Though it is largely empty, it is lethal, and a part of me will/would always fear what may lurk in it.   This could really benefit from snippets tied into religious creation myths or superstitions overall. Are there any special beliefs for what happens when you die in the Abyss? Who was the first person to dare explore it? Was there a Water Wars to match Earth's Space Wars? If people made a dome of their own (if they're planning to) do they have an idea on how to give gravity to it?   All in all, this opens up a ton of questions about the nature of the world and the things in it. It's the first article about the world itself that I've really read, and it has me reeling, thinking I need to find the starting point and learn what's really up.

Admin of the WA Codex & Discord

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Master Redclaw123
Elias Redclaw
7 Jun, 2019 12:58

Holy moly. Now this is what I call a masterpiece. This has probably got to be one of the most horrifying replacements of space that I have personally seen in fiction. The article manages to be true to its name, a mysterious abyss who’s main horror is the unknown, similar to lovecraftian horror I’d say. The article is amazing and beautiful for such a small article and I’d say that I loved it! The only issue I saw was that in the second line of the “life” paragraph, you write microscopic as microscoping and plankton as plancton but then again these are very minor nitpicks. One question I had though was that have the corporations ever constructed any outposts In the abyss or some sort of large scale settlement? Have they ever perhaps even tried to “terraform” the abyss? Anyways this was again an extremely good article and I loved reading it! Congratulations and keep the amazing and goddamned hard work up tobs!

Grandmaster kvm
Konstantin Mika
25 Jan, 2020 20:34

This is really intriguing, makes me want to explore the place, and the science-y part of me has questions. For instance, who built the dome, and why? (Based on other comments I assume there won't be a clear answer to that, which is fair.) What, if anything, is beyond the Abyss? Do ppl have similar beliefs to ppl on Earth re "just bc we haven't found that other world yet, doesn't mean it doesn't exist"? I really like the nav systems, esp the ABN. Really drives home that "alone in a hostile sea of darkness" feel. Great writing and worldbuilding, as usual!

8 Jun, 2021 18:50

The dome question will likely never be straight up answered, mostly because I feel it'll just be a meta-explanation. If someone created it, who created them? And who created that which created them etc. For now, it's no different than our own universe. Who created the stars? Who created our planet? It's just there.   And yes, the Dunians are constantly searching for other, populated "planets" or Islands. Considering they've found both flora and fauna in the Abyss, somewhere there must be intelligent life, right?   What's beyond the Abyss? That, my friend, is for patrons only ;) Deep-dive historians have access to my "behind-the-scenes" world, which contain a lot more information of the actual inner workings of Dunia and the universe of Celenia.

Author of prize-winning RPG settings Dark Shadows and Cinders of the Cataclysm. Designer of the narratively focused CD10.
29 Jan, 2020 17:23

Ooh, you have added bouys since I read this last. Very logical progression, I like it!   Still a very creepy situation. Those poor colonists.

Author of Fillimet, bright fantasy land of possibilities, and Vazdimet, its darker spacefaring future.
Eternal Sage AmélieIS
Amélie I. S. Debruyne
8 Jun, 2021 17:25

I love this take on "space", all the limits you've put into the explorations and the technologies that have been developed to overcome this :D Just the imagery of a small flat world surrounded by infinite water is very powerful - and very frightening! I'm also very curious about all the life potential there hiding in the dark , just waiting to eat something :p

To see what I am up to, my latest article is a choose-your-own-adventure story featuring a job interview to become one of the Dark Lord's evil minions :D
8 Jun, 2021 23:07

Very interesting replacement for regular space. It really gives it a more horror feel, especially since not seeing the ground while swimming in the sea always made me uncomfortable. And you made everything outside the world that way :p   I like how you keep the mystery somewhat about what kind of creatures there could still lurk in the deeper areas of the Abyss. The ways that the people cicrumvented the navigation problems to a degree was a nice addition as well.

Feel free to check out my River challenge article and my Secrets in the swamp Adventure article if you want to see what I am up to!
9 Jun, 2021 17:48

This is super fascinating! Great way to re-imagine "space". Since the world is shielded from the abyss, I suppose it might be a benefit that the water of the Abyss is so cold that it freezes on contact with air -- almost like if a leak happens, it's self sealing?   The final tease of colossal monstrosities living in the Abyss is icing on the cake, too.

Cathedris, the world of God-husks and New Magic, welcomes you.
10 Jan, 2022 10:23

I suppose it might be a benefit that the water of the Abyss is so cold that it freezes on contact with air -- almost like if a leak happens, it's self sealing?
Uh...yes...yes, absolutely! This is absolutely what I had in mind when I came up with that idea. Yep!

Author of prize-winning RPG settings Dark Shadows and Cinders of the Cataclysm. Designer of the narratively focused CD10.
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