The fifth plane of the Nine Hells derives its name from the Styx, the mighty river of black, opaque water that falls from the endless encircling mountains and swells into a vast salt swamp that fills much of the plane.
Stygia is ruled by Geryon from his huge castle, Tantlin, which lies at the center of the plane, the swamp curving about it for slightly less than half the run of its high stone walls.
Stygia is a chilly place, lit by lightning flashes and “cold fires” (weird white flames that are freezing cold and do damage while in contact) that burn on rocky peaks for some time after a lightning strike. It is not known precisely what these flames feed on – they appear to blaze on bare rock – and they leave no trace on rock or ice.
Much of Stygia’s landscape is high, tumbled rock and ice. Avalanches and electrical storms are common, and “shooting stars” of ice sometimes hurtle across the sky from the peaks, smoking, to plunge into the swamp far below.
The swamp itself is constantly disturbed by splashes and wails, for it is the abode of the styx devils, who torment lemures constantly unless summoned by Geryon to undertake a mission. Sometimes a bone devil or horned devil will enter the swamp to join in the fun, or to chase a few styx devils, but on such occasions all of the styx devils present will eventually unite to drive them out.
Beneath the swamp lies a cold and lightless ocean, home to giant octopi and squids, whales, and many smaller, blind fish. There are no sharks or killer whales, however, for in the utter depths Sekolah, a great white shark, cruises. She long ago devoured all potential rivals, and now swims supreme, ignored by the devils, as the ruler of her deep realm.
If there ever was an aquatic race of any sort at the bottom of this black river – sahuagin, diabolic, or otherwise – there is none now. The sahuagin of the Prime Material Plane worship Sekolah but she appears totally disinterested in all matters except where her next meal is coming from.
Much of the upper reaches of the ocean are always frozen (if they were not, much of the vegetation that makes up the swamp would have sunk to the ocean floor long ago), and Sekolah very rarely comes to the surface. When she does, lemures, hell hounds, and devils alike usually make a hasty exit from the surrounding area.
Geryon seldom leaves his great castle. He delights in physically battling lesser devils and captured intruders within the walls of Tantlin, sometimes chasing them for long periods of time throughout the halls of the castle and the gravel-strewn mines nearby, where Tantlin’s blocks were and still are quarried, eternally, by captives, spined and barbed devils, and the like. Geryon delights in luring powerful creatures from other planes (that is, from outside the hells) to Stygia with carefully contrived tales of magic, lore, or other treasure, so that they can be the victims for one of his cruel hunts. Any survivors of these unsporting events go to the quarries. (Geryon, by the way, is immune to the strength-sapping power of the bone devils tail poison.)
One of the most powerful members of Geryon’s retinue (assistant advisor) is Herodias, whose title is magistrate. Herodias is responsible for the security of the realm and the training and ordering of Geryon’s legions of bone devils, and for assuming command of the defenses of Tantlin whenever Geryon is hunting.
Geryon’s bailiff, Gorson, concentrates on external matters. It is Gorson who observes the day- to-day activities and internal politics of the other planes of the Nine Hells, and who (unless Geryon steps in to do this directly) orders and coordinates the styx devils in their individual missions about the planes.
Geryon is perhaps the most satisfied or contented of the archdevils, and the least interested in the endless political struggle among the devils for more power, although he never misses a chance to act to the detriment of his foe Moloch, ruler of the sixth plane, or his other neighbor, Belial.
Herodias and Gorson safeguard his interests (under the watchful eye of Cozbi, Geryon’s consort), gaining much actual power while always acting in Geryon’s name, and allowing Geryon to continue his “hunts” by, if not increasing his force and influence, at least preventing their erosion.
Newcomers to Stygia will find that it is cold (why the swamp and the river Styx do not freeze is a mystery to one accustomed to conditions on the Prime Material Plane), with little shelter outside Tantlin, and there is nothing to eat unless one has a taste for the flesh of devils, lemures or hell hounds. (It is not certain if such flesh is edible by humans. Some mad adventurers in the Realms have boasted of eating the flesh of devils, but the truth of their claims is unknown.
If their words are true, it is impossible to say if such food is poisonous to some, carries any diseases or parasites, or if it in fact has caused their mental conditions.) Tantlin, however, is said to be richly provisioned and furnished, crammed with the bric-a-brac of centuries of plundering the wealth of other planes. (Before he gained the rulership of his own plane, Geryon was wont to undertake extended pillaging expeditions through the Prime Material Plane whenever summoned there by a foolish mortal – and he always sought out the most dangerous, and richest, foes.)
Geryon’s vassals are outwardly loyal, and are often called upon to protect their master’s interests. They include Amon, who commands 40 companies of bone devils; Agares, who commands 31 companies of bone devils; Machalas, who leads 11 companies of barbed devils; and the pit fiend Fecor, who leads 8 companies of Malebranche (“Evil Claws”).
The fiefs of these dukes lie between Tantlin itself and the rockiest heights of the endless, frozen mountains, consisting of rising land and many long, twisting rocky canyons and hanging valleys. There are a few remote volcanic rifts in the mountains, commonly known as “steam trenches,” where the Malebranche dwell unless ordered elsewhere.