While there is a mystery, the main thrust of this novel is split between geological explanations of plate tectonics and the personal life of Em Hansen. The on-going friendships she is developing with Faye and Tom are interesting and the characters are likable. What really ruined my enjoyment of the novel were the on-going inaccuracies in the way Ms. Andrews portrayed Mormons. Just a few examples: Mormon missions last two years, not one. Any Mormon who is as straight-arrow as Ray is portrayed would not have gotten married at 19 - he'd be on one of those two year missions. And you'd be hard pressed to find a place to rent in Salt Lake City where anyone would care if you had a member of the opposite sex in your space. Finally - I don't really know any Mormon women (myself included) that figure our role in life is to be subservient to our spouses and to get busy making babies. After three novels set in this environment, it seems to me that Ms. Andrews would have invested a little more time in making the setting realistic instead of just using stereotypes. It made the mystery less believable because much of it rested on these faulty assumptions. ( )