I started this because the first few pages held the appeal of a Twilight Zone episode to me: mundane people juxtaposed with a high-concept scifi element that communicates something about human nature. It ended up being an appeal that persisted, in that each chapter felt episodic - revealing, complete, and satisfying. I think you'd be hard-pressed to describe the "plot" - each chapter has its own internal plot that is resolved, to some extent, by chapter's end. I wonder if this book started as "connected short stories". A compelling but odd reading experience.