Hall of Infinite Doors

Carefully you lower yourself over the side of the hole and grab hold of the ladder. It takes but a few seconds for you to descend far enough that you can't see anything of the tunnel around you; the hallway above shows as a circle of white light, slowly diminishing as you climb down. It gets damp and muggy quickly, and though the shaft is roomy enough that you don't scrape yourself on anything even in your blindness, you can't help but feel entirely encapsulated by the earth.

The ground comes as a bit of a shock, even if you know it's coming; one second you're dangling your foot vaguely downwards, the next a craggy stone surface is pressing up against it. You test the floor and then step down uneasily, keeping your hand to the wall to have some idea of where you are. You feel around a bit and find yourself at the bottom of a concrete circular shaft; there's an opening, directly across from the ladder, and it feels somewhat rough, as if it was bashed or eroded away rather than constructed. There's a wet, hot wind shuddering constantly towards you from out of that black tunnel, and the noise is clearer here, an unhearable animal murmur and some unidentifiable hissing.

Still, where else is there to go? You feel your way along the sides of the tunnel, groping forward through the blackness into gods know where. The tunnel slopes and dips faintly, but always in a way that surprises you, taking away familiar handholds or leaving a low pit where the floor should be. You're descending, you know that; the earth surrounds you on all sides. You can practically feel its massive weight above you, pushing you down, down and down.

Eventually you stumble almost face-first into a wall. A bit of feeling reveals that it's a bend, a blind turn right and downward - well, almost blind. There's a smear of color almost imperceptible upon the lower rocks, a russet gash reflected, somewhere, from below. There's light down there. And the more you descend, the brighter it gets, until the entire rough tunnel is dimly illuminated in a ruddy red glow.

Suddenly, you round a bend and come across a bright end to the tunnel. It's far more luminous than anything you've encountered so far; so much so that it blinds you for a moment, spearing your eyes with bright orange and white and blasting your face with a belch of furnace heat, so that it takes you a while for you to see what you are on the threshold of...