It is morning and the stairway is still there.
What do you do? Up again or down?
Going to the stairway and peering down into the darkness you listen intently and hear faint sounds, some coming up from below and some coming down from above.
What do you do?
Which should you explore, continue from yesterday or start downward? This place is massive, where to start or should you go recruit a much larger group?
You start down the stairway and at the first landing you look around. The stairway opens into a very large room, with all the light at your disposal you cannot see any walls in any direction. You do see many supporting columns in every direction but no walls.
What do you do?
If you decide to explore this open area, one of your party fastens a number of light stones around the stairway so that you will have a beacon to return to.
Coordinating with someone at ground level on the stairway you mark the four points of the world around the stairway and decide to head east. You walk forward and stop every 20 paces to listen quietly and look around. You hear nothing as you do this. As you come to each column you mark it to help find your way back.
After 200 paces the light stones have grown very faint, you decide to keep going. When you stop at 2,000 paces, you listen and in the distance ahead you hear, what you think is the roar of moving water. You rest, eat and decide to continue.
Another 1,000 paces and you come to a river that is about 200' wide, the water is fast moving and clear enough that your light stones let you see the bottom in a small area. You tie three 10' poles together and they just reach the bottom where you are on the bank. At the edge of your light you see large shapes in the water.
What do you do?