Finished Reading Asimov's Pebble in the Sky

I just finished reading Pebble in the Sky, Isaac Asimov's final novel in his science fiction Empire trilogy.  The stories in this trilogy are connected with each other only in the context of the backdrop of Asimov's make-believe future of the growing galactic empire of Trantor.  The characters, stories, and locations are all completely different and are separated by vast spans of time, one book having no discernible bearing on any of the others.  Pebble in the Sky takes place on Earth, with a visiting archaeologist from the Sirius system and an accidental time traveler from "our" contemporary Earth's Chicago making up a pair of highly unlikely protagonists.  The Earth's population has dwindled to number in the millions and residual radiation from a devastating nuclear war in eons past (i.e. our time) has polluted the planet.  The other star systems in the galactic empire treat Earthlings as pariahs and they respond in kind with a surly, rebellious demeanor.  Throw in a scientist's discovery of a formula for intelligence enhancement, a society in which people are put to death at age 60,  and an insidious plot against the rest of the galaxy, and you pretty much have the basic ingredients of this story.  It was more enjoyable to read than the previous two Empire novels, but I felt that Asimov threw too many gimmicks into his tale. Still, it's always fun to read others' speculations about our future.

There, I've read Asimov's Empire series again.  Now to continue with his much better and more cohesive Foundation series...which consists of five basic books, two prequels, and at least three posthumous spinoffs written by other authors...