An abandoned temple.

The slow descent casts a light breeze on your face, and the air around you grows both cooler and wetter. After a moment, you hear a splash in the dark a short distance beneath you. Then a second, louder splash. Rosaria and Beatrice, you assume and withdraw a heart-sized glass orb, etched with arcane script. A paltry trinket, but you knew buying a Driftglobe would eventually pay off.

"Light," you speak aloud. Just in time to illuminate the vast underground lake below you. Splash! Seawater fills your mouth and your robes immediately begin weighing you down. You see a strong, pale form swim toward you, and Beatrice wraps a muscled arm around your waist. Her powerful legs carry you both to the surface, and a second later the driftglobe bobs up to the surface before rising a foot above the dark water. With three times the light of a torch, the globe offers enough clarity to see the sloping, unworked stone ceiling.

"What's that?" Helena calls out from your right. You and Beatrice both look her way. In the dim shadows beyond the globe's aura you spy the silhoette of a domed building sitting atop the dark lake's rocky shore. Civilization? This far beneath the earth? Your studies mentioned a few possible creators: drow, duergar, perhaps even the fabled 'mindflayers', though none of the squid-faced horrors had ever been found alive or dead.

The four of you swim toward the shore, guided along by the silent, floating globe. Beatrice hefts you out of the water like a wet cat. To your mild embarassment, none of the ladies have trouble climbing up, but then again you are the only one wearing robes. Trusting the sharp eyes and ears of the others to keep you safe for the moment, you wring the water out of your clothes as best you can.

"Woah, what's THAT?!" Helena chirped, jabbing a finger up toward the building. Your gaze follows her finger upward. Ah, well that could be troubling. Drow, duergar, and mindflayers might have been a preferable ****. Demons were such fickle masters, and they hated few things more than rivals. Here before you stood a temple bearing tall windows of blue, green, and teal stained glass. A vaulted, double door carved from teak held all manner of eldritch markings and piscine imagery. Twin gargoyles loomed to either side of the door, each sporting bulding eyes, a gaping maw of needle-like teeth, and webbed hands and feet.

"That, my dears, is a temple of Dagon," you say, the last word catching in your throat like poison. Among the demon lords, Dagon was one of the oldest, and likely the closest thing Grevakhnu has to a rival in the Abyss. If you left here now, the abyss mother would see you rended limb from limb. ****, then. "Perhaps there is a way out inside," you tap your chin and decide to take the lead this time. Unlike mere mines and merchant lords, the nuances of the Abyss must be dealt with by a true sage. Stepping to the heavy, wooden door, you ponder your next actions to honor Grevakhnu and denounce Dagon.