Sarah Andrews' newest geological mystery finds geologist and investigator Em Hansen helping out the Salt Lake City police on the murder of a fellow geologist. Dumped in a gravel quarry, his arms and legs removed and his face bashed in so he'll be unrecognizable, Em IDs him anyway because of a strange tattoo--a geological map of the world--she spots on his body: It's Afton McWain, a controversial figure who worked in big oil in Colorado but who now works in the field of water and droughts.