Red Depths Mythos

The Red Velvet Desert plays host to small populations of Rostrans, some extant and some deceased, who live semi-nomadic lifestyles among that region's rocky islands and ever-shifting seas of crimson silt. The shattered hulks of previous vehicles and settlements dot the landscape, a testament to the harsh realities of desert living.
Still, many believe, there remain even greater ruins secreted away in trenches, hollows, and caverns beneath the sands, waiting to be discovered - evidence, some say, of a vast, advanced civilization which dominated the Manifold Sky before even The Curved Time. Others speak of huge, ancient beasts with segmental, serpentine forms which lurk beneath the sands like sharks in the ocean, implying that these beasts might have served the ancient peoples before going out of control and consuming their masters. Still others speak of the howls and whispers of mad ghosts which manifest in the fevered minds of individuals trapped to long among dunes which the wind makes sing. The stories of these and other fantastical aspects to the Red Velved Desert are known colloquially as the Red Depths Mythos.

Summary

The Red Depths Mythos typically covers a variety of conjectures surrounding lost technologies, lost civilizations, cryptids, and the ghosts of the dead which may be found in the Red Velvet Desert. The Mythos is not an entirely cohesive mythology, as one might find among the many religions of the Manifold Sky, but stories within it always feature themes of loss, forgetfulness, and paranoia.

Historical Basis

It is true that there are long-dormant lava tubes lying between the silt of the Red Desert's surface above and the magma at the level of the commissures below. In truth, these caverns are simply the remains of fragile iron-rich lava structures which, over geological time, were eroded away to create that same silt. In present day, most of these lava tubes have filled with ground water, becoming important sources for the rare springs and aquifers upon which the Rostran surface-dwellers subside.
It is also true that abandoned vehicles and structures will eventually become buried in the desert sand and, eventually, find their way to the bottom of the silt seas - coming to rest at such depths that no explorer will ever likely find them. Occasionally, miners in the region will uncover bits of old pottery or even the odd mummified humanoid remains, usually dating to the first or second millenia AE. These bits of evidence may point to the presence of a long-extinct Lost Tribe, though the identity of these ancient humanoids remains lost to history as of the modern year of 10,000 AR.

Cultural Reception

Among anthropologists, it is believed that the Red Velvet Mythos is a Rostran culture-specific response to the natural danger and privation of desert living. The Mythos is a folkloric cannon which allows those living in the Red Velvet Desert to justify not travelling alone or exploring dangerous-but-curious locations they might encounter whether or not the individual understands the exact nature of the danger involved on an intellectual level. This taboo-delineating aspect of the Mythos, therefore, fills a social role akin to that of the Ovistrix of Rostran Archipelago Confederacy mythology, albeit with a practical (rather than moral) twist.
The Mythos may also be regarded as a way of mythologizing the dissappearances of those lost among the silt seas, perhaps eventually serving as the basis of a new religious movement one day (i.e. an offshoot of Ixa Ad-Korvidiu). As of the year 10,000 AR, many locals speak of the ruins and bodies which might be found beneath the silt as though it were an entirely different plane of existence, akin to the way that the epicyclist Rostran Esotericism system of belief speaks of The Curved Time as a spiritual place of existence both before and after the existence of the material world.