Which throws off the first two versions entirely.
I'll go into the top one first. I'd pictured it as a stark image, running up cavern stairs. It's flat, because I'm aiming more for a mood than a representation – I'd even considered doing it just as a pure silhouette in just black or purple. So since it's what I had in mind, I could just leave it as is and call it finished.
However, I did show it to a friend, who said that the stairs could pop out from the background more, I could add more color to the figures, and so on. All valid critiques, I'll be the first to say, if I'm trying to represent it dimensionally.
Now on to version 3. While I was debating all this, I realized that the figures aren't necessarily supposed to be suspended in space, on a narrow stairway. It almost looks a little like the Bridge of Khazad-Dum from Tolkien. So I thought about how it would look if they are going up a labyrinth of stairs, and came up with drawing 2.
In some ways I like it better, especially with the other wanderers climbing the stairway along with them. It would mean starting again, of course, but it's worth it if it makes a better illustration. I'll have to figure out which direction to go here, but if anyone wants to chime in, I'd welcome people's opinions!