This final book of the original trilogy was weaker than the first two by quite a bit. The first story (Search By the Mule) is more of a conclusion to the cliffhanger from the second book. The second story is a conclusion (of sorts) to the first trilogy. Both stories rely on a convoluted web of reverse psychology (and reverse psychology backfire), and are annoying to read. Perhaps because of these intricacies, the characters are all mostly flat. 2½ stars, rounded up because Isaac Asimov was just so darned smart.