Skidding to a halt, your eyes take a moment to adjust to the subdued lighting. When they finally do, you are greeted with one of the most astounding sights you can imagine. Stretching out into the darkness for what must be several miles is a foggy cavern, the rock comprising the ceiling, walls, and floor possessing a luminescent blue tint. Equally impressive is the spectacle of a wide river which encompasses nearly the entirety of currently visible cavern. No waves or even ripples mar the surface of the river, making it seem to be just a pool of standing water, but upon careful examination you can see a steady stream of random flotsam floating from right to left across your vision, proving that the water does have a flow to it. Much like the cavern, the river itself seems to provide a strange glow, but after peering into the depths you discover that the light is actually provided by small glowing motes which are floating along with the current.
Becoming wrapped up in the alien nature of your current locale, you are only broken away from your gawking by a creaking noise emanating from somewhere out on the river. Looking out into the fog, at first you see nothing, but slowly the prow of a wooden boat begins to emerge from the mists. At around twelve feet long and possessing none of the luxuries of modern boating, the vessel looks to be fairly unimpressive. This analysis of the craft remains only until you notice that it isn't floating upon the river, it is floating above the surface, seemingly gliding on air. Turning as it makes its approach to the shore, you spot a man in dark robes standing at the stern, but none of his features are visible to you through the darkness and the fog. Pulling even with the shore, the boat comes to a stop and then just sits there, the hooded head of the man turning to regard your presence. Not making any other movement, the boat and her pilot merely hover there, as if waiting, and you feel compelled to walk over to it. Upon reaching the boat, you are able to see the man more clearly, though the visage of what turns out to be a gaunt, middle-aged man is something of an anticlimax given the circumstances.
"Well, it has been a long time since we have had anyone pass through here," the man says, his expression never drifting from a disinterested frown. "I wonder, did you defeat Cerberus in combat, or merely sneak past him?"
Having no idea of what the man is talking about, you just stand there with a bewildered look on your face.
"Well, no matter. I imagine you desire passage across Styx, and I can certainly grant you that, for a price," he says, turning and indicating a chest sitting behind him which you had heretofore overlooked.
With the strangeness of the situation beginning to eat away at your nerves, you fidget nervously and try to decide upon a course of action.