From publisher blurb:
The Grand Stair stretches behind the scenes of the multiverse,
The Doors upon its unfathomably vast span leading the way to gossamer worlds of limitless variety and infinite possibility. Some worlds last forever. Some worlds burn.
Ring of Fire is a ring-world that once provided living space for millions of species on a miraculous hoop encircling a shining star, until the day an evil force turned the sun into a weapon and doomed most of the world to the harsh glare of eternal high noon. Nowadays, a line of scorching sunlight encroaches mile by mile, and the only way to stay alive is to march westward across the frontier. The Walking West is an ever-trudging land of gunslingers and golems, preachers and pilgrims, steam-craft and survival. Head west, my sons, and know that while all the world marches with you, death marches behind you.