Synopsis: As far as anyone knows, all mankind lived in the City. The City, a self-enclosed towering single building had always moved generation by generation across the vast empty landscape. Brann Adelran met destiny when his family sector found itself at Tailend. Already the Structors were planning to dismantle his ancestral apartment high on an upper floor of that colossal metropolis. Brann would have to make the pilgrimage to Frontend to re-establish his family there for the generations to come. But when tradition was suddenly shattered, Brann was forced to flee, not on the established routes and hallways, but down the forbidden shafts into the lost chambers, corridors and basements which even legend had forgotten. (adapted from the back cover of the first edition)