This book is about how a comet hits the earth, how people prepare for it, and the aftermath. It follows various story lines, mostly set in California, and ties them altogether in the end.
My favorite sections were the little scientific summaries and global descriptions that often preceded the narrative in the various chapters. Some of the conversation feels a bit dated and corny, but overall I really enjoyed it.
Underlying the whole book, which is full of action and suspense, is a real foundational question: what is civilization? The authors handle it with delicacy and tact.