When you live at the bottom, the only thing you have is to look up. If you're lucky you can see the lights of the great towers and the stars. If you're like most people, you just look at concrete. But the stars and lights are still up there.
Could come across a band of refugees. Could have been thrown out of their town by a tyrant taking of their land, bought out by somebody unexpectedly, fleeing a battle they know is coming their way. Could be proof of what they are searching for, hints and tips of what is to come, or just to broaden the reality of the world.