Beneath even the lower caste level and spanning the entirety of Haviah lies an undercity, a filthy, warren-like slums that sunlight never reaches. The city begins a bit below where the lower level ends, extending upwards into the metal warren of the lower part of the city and then downwards deep into the earth, where it branches out beneath the city. It is nigh impossible to enter the undercity unless you know where to look, for the lower caste level is completely sealed off from the undercity save for some hard to find and often overlooked openings. Thus, travel between the two is rare.
This undercity is known as The Midhaven to its people, who are Haviah's forgotten: vagrants who have fallen between the cracks and been left behind as the city continued to build upward. The people of The Midhaven know a crude sense of freedom as most go unmicrochipped (they wouldn't even know what a microchip is) and the government has largely abandoned them, Pilots only visiting for the occasional raid when they do something rowdy to remind people that they are down there. Dragons, of course, are far too large to go down there.
Because of their lack of microchips and because they are ignored, they are often referred to as "figments" (sometimes shortened to "figs") by the government. They have no microchip and thus they do not exist, and the government does not view the animal-like, technology-lacking figs as a big enough threat to be concerned with them.
Of course, the inhabitants themselves do not refer to themselves in that manner.
A bleak and brutal place, The Midhaven is a world of perpetual twilight, named because it is the only safe haven between the devouring darkness below them and the burning light above them. It is a world of limited technology and its inhabitants live in an almost constant state of fear—fear of each other in a world where competition is fierce, and fear of the world above. They know there is something above them; some talk of an enormous city and flying beasts. But no one who has ever ventured upwards into the light is ever seen again. It is this fear which keeps them from growing too organized or too rowdy under the belief that if you get too ambitious, you may incite the wrath of the gods above and be swept into the light, never to return. It's a justified concern, too, considering past raids by Pilots which have further reinforced these views.
The only way out, for anyone brave enough to try it, is to go deep into the pitch black darkness of the earth and hope that the rumored others find them and take them to their free city—Teinar.
For survival's sake, the people of The Midhaven tend to group together in tightly knit gangs, or "packs" as they call them. Beliefs and values vary from pack to pack, though there are some core beliefs they all have in common, and there are many bitter rivalries between them, as competition over resources is fierce and often bloody. With the lack of food down there, some packs have turned to cannibalism and hunt other packs, both for food and under the belief that they are consuming the spirit and strength of their enemies in consuming their flesh. Cannibalistic packs also often feed on their own dead, the ones that aren't diseased at least (though in that sense the practice takes on a more respectful, ritualistic light), for space is limited and other methods of disposing of bodies (burning, burial) is impractical.
Like anywhere else, sometimes a psychic is born in The Midhaven. Views regarding psychics also vary; one pack might revere a psychic as godlike, another might sacrifice them, and another might view them as dangerous and kill them upon discovery. A psychic born in The Midhaven and discovered by a Pilot would be taken into Haviah and put into the Pilot Candidate program, though this is a highly rare occurrence as Pilots don't venture down there often, and the chances of finding a psychic are slim.
As for the people themselves on an individual level, they tend to be very pale. There is no sunlight down there, and thus no tans. Hygiene levels are also not the best, to put it lightly.
While beliefs from pack to pack do vary, there are some core beliefs and practices they all have in common.
Brutal as the place is, death is everywhere and thus also an important part of their beliefs. As burning and burying their dead is impractical, they had to find another way to deal with the problem. Cannibalistic packs solved the problem by eating their dead, but even they had to deal with finding a way to dispose of the diseased, inedible ones, and throwing them to the beasts that prowl the underground was not an option.
There is an underground river that flows through The Midhaven, tainted with mercury and thus unfit for drinking, but this river is sacred to its people. Called the River of Souls, it is a holy place where all packs can go without fear of hostilities, a place where fighting is prohibited, and it is into this river that the dead are deposited. Packs may have different rituals and ways of doing it—some might float their dead, others might weigh them down—but the common belief is that the river runs in a circle and will thus deliver the souls of the dead back to them by reincarnation. Another variation of the belief is that the river delivers souls into freedom. Either way, because the river is also tainted by mercury it keeps any animals away from the bodies so that the souls do not become lost and turned into demons.
Naming patterns also vary between packs, but many have adopted a more basic naming system and name their children after features they possess, the environment, personality traits, and things like that. Babies are usually not named right away, in case they die.
Another shared, core belief is that females are mystics and Timekeepers and quite central to their way of life. In a world of constant twilight, they have no concept of days. Instead, they measure time by female's blood cycles, so a month for them would be called a "cycle". And while they still call it a year, they have redefined the term to mean a period of nine cycles, the average length of a pregnancy.
Most coveted among the packs are women with full buttocks and thighs. Not only are they viewed as highly beautiful, but they are also viewed as ideal for bearing children and other packs often try to steal them. Similarly, packs tend to be highly communal, with children being raised by the entire pack. A woman's daughter is not just her daughter, but the pack's daughter.
Numbers sacred to the packs are the numbers nine and three, nine representing a woman's gestation period, and three as it represents life, death, and rebirth, and also darkness, twilight, and light. It is also the square root of nine.
As stated earlier, the technology level in The Midhaven is extremely low, and while the packs know of electricity and firearms, actually finding any is a different matter entirely. Firearms are rare. Working firearms are even more uncommon. Sometimes a pack might find one and be able to fix it, but for the most part their technology and weapons are crude. Think daggers and spears and the like.
The dangers are not limited to other people—there are also a variety of animals that share the same living space. These animals are not mutated, like the ones in Teinar, they are simply creatures native to the underground. Some of these creatures are small and mostly harmless, but it's the ones that they can't see, the big ones that lurk in the shadows, that they have to worry about.
Most people haven't actually seen what these creatures look like (at least, not the ones that have lived to tell the tale) but everyone knows about them and most have at least heard one, if not seen someone get dragged into the darkness by one. There are a lot of beliefs and folklore surrounding these beasts, and a common one is the belief that they are lost souls—and that anyone that gets taken by them also joins them in eternal darkness. Thus, packs are very protective about their dead, for they must never let them be taken.