A network of flooded, fractured caverns radiate outwards from beneath the Murkwater. The water therein is only fractionally above freezing and explorers need magic to survive for any length of time in this airless, lightless world.
Blind and colourless fish swarm through these tunnels in vast numbers. A ferocious subspecies of giant moray eels prowl these waters. Grown accustomed to the perpetual darkness these creatures rarely emerge from their labyrinthine hunting grounds instead growing fat hunting the fish swarming in the tunnels.
Few adventurers willingly enter the Breathless Narrows. The combination of utter darkness, freezing water and strong, but unpredictable, tides (along with the large and savage eels) make the place a deathtrap for those without powerful magical protections.
In several places, the Breathless Narrows intersects with the Murkwater. During stormy weather water flowing into and out of these vertical shafts creates powerful whirlpools that can drag the unwary — or unlucky — down to a suffocating, terrifying death.
However, more lurks beneath the frigid waters of the Breathless Narrows than mere fish and the splintered remains of mouldering shipwreck. For while they are one of the least populated levels of Gloamhold life yet flourishes — or at least endures — in this remote, dangerous place.
In the outermost region of the Breathless Narrows, where the inundate caverns intersect the Pens below Rivengate, explorers report a greater prevalence of undead. Some stories place a powerful undead spellcaster of indeterminate sort in the area while others speak of caverns choked with bones and the mouldering remains of ancient shipwrecks. Still other legends speak of a near-impossible-to-reach sub-level of air-filled caverns far below the Breathless Narrows. How the caverns remain water-free, and what lurks within, is unknown.
The Breathless Narrows also connect with the Sunless Lake wherein stands the Twilight City. No reliable map of such a route exists, but several adventurers claim to have fled that way after being all but overrun by the troglodyte tribes lurking within the city’s bounds.
Fane of the Shadow Lord
Persistent rumour places a sunken shrine of dedicated to the Shadow in the Sea somewhere in the Breathless Narrows. Guarded by a small cult of fanatical, deranged, and hideously deformed, skum the shrine has remained hidden despite the misguided attempts of several bands of adventurers to sack the place.
The unholy bastion of Dagon lurks in a particularly deep part of the Breathless Narrows. Strong tides course through the surrounding sunken passageways making the fane hard to reach for creatures without natural swim speeds. Monstrously large and bloated fish lurk in these turbulent waters. Ever-hungry, they savagely attack all interlopers. Bones — often stirred up into great swirling clouds by the vicious tides — cover the floor of these caverns and can cause considerable harm to those caught in them.
The Deep Cave
In one section of particularly narrow and convoluted passageways, the water gets even colder. The familiar vicious tides, huge fish and predatory eels prevalent elsewhere are strangely absent here.
Rather, the near-frozen waters seems to flow sluggishly out of the passages. One adventurer who fled into this area after his companions fell to the attentions of the Breathless Narrows merciless denizens spoke of a narrow, but impossibly deep, cavern from which this cold water flowed. Terrified, and only interested in escape, he did not stop to investigate the phenomena and thus the mystery of what lies within remains.