Half of this book was about average, the other half incredible -- so the total comes out to really rather good! Even the average story, about post-apocalyptic people looking for a new home, might have been worth reading, but what really grabbed my interest was the half of the story dealing with the birth of a spider civilization. No rubber forehead aliens here - the spiders felt really strange yet understandable. This was truly excellent and imaginative stuff with an ending I really loved.