Reading science fiction in year order from the 50s shows just what a decade of change the 60s was, and this novel was the apex. While grand science fiction, it is also a human story which really took off halfway through the book, with both main characters on the run.

I won't try and summarize the book, and could barely scratch the surface of deeper meaning that other reviewers have found. Let's just say I agree completely with the Hugo and Nebula wins, its inclusion in the "defining science fiction of the 60s" list, along with nearly every other top science fiction list. Recommended!