I noticed this book on my shelf the other day and decided to reread it (only I had to buy the kindle edition because I can no longer read physical books). I think I must have originally read this when I was in high school, back in the dark ages. It has held up remarkably well. The book is still entertaining. The characters are interesting, the plot believable (even if a little outdated scientifically). It reminds me of why I started reading science fiction in the first place.Although it is billed as the third book in the Galactic Empire series, it stands very well on its own, something I really appreciate in a series book.
If you haven't read Asimov, if you think classical science fiction might be boring, think again. Pebble in the Sky is as good a place as any to quaint yourself with some of the best writing this genre has to offer.