First printing (number line). Ex-library with expected stamps, labels, tags, and paste downs. Properly de-accessioned. Tight, clean, flat, square, sharp and crisp book in protected dust jacket. Part I (Pages 15-149) is an almost identical reprint of Clarke's novella "Against the Fall of Night". According to most sources (and alluded to in Clarke's Foreword) Part II was written solely by Benford.

 What’s left of humanity is confined to a single, magnificent city: Diaspar. The rest of the world seems to be a vast desert. Alvin--only a boy when the book begins--dreams of exploring the world beyond the city, but society frowns upon such dreams. It's not even certain how one could exit the city. There seems to be no break in the walls that enclose it. There are hints of some sort of ancient battle fought against alien forces known simply as “the Invaders. “ But, as with leaving the city, the very subject seems to be taboo …

Alvin does eventually leave Diaspar, and his actions eventually have dire consequences that are explored in Gregory Benford’s portion of the book. The entire book is essentially a travelogue, first of Alvin’s journey, and then of Cley, a genetically engineered Ur-human who ventures off-planet in an attempt to escape from … but you’ll have to read the book for that.