The stories follows loosely the extended Ferguson family: father (a disgruntled cop in LA), mother (freshly divorced, falling for her yoga instructor), two sons (band singer and long term college student), daughter (professional malcontent) and her ex-boyfriend (academic of unpractical science).
With a starting title like "Eruption" and the authors reputation for fast paced action, you would expect the supervolcano to blast it all spectacularly to pieces. But you get served with a slow-motion-landslide burying the struggling victims. Instead of lava bombs, the characters rather get hit by a falling economy instead. This does not improve the fun upon reading.
While a death spiral of U.S.A. in the aftermath of the gigantic disaster may sound interesting, the sluggish tempo takes a heavy toll on the reader as well. While i think this to be an intentional choice by the author to offer an alternative to a cataclysmic end of the world scenario, i would say he has overdone it in this books. The gems, the surprising insights i got in heaps from a lot of his other novels, they were rather rare finds in the three books. A 3:1 compression would greatly improve this series.
I would recommend this books only to his die-hard fans. If you are among them, you can start here on Amazon.