A second adventure for geologist Emily (``call me Em'') Hansen--reared in Wyoming, schooled in her aristocratic grandmother's Boston. On her first job, the menial one of mud- logger in an oil field, Em had helped solve the murder of head geologist Bill Kretzmer (Tensleep, 1994). Now, sharing the apartment of his widow, Elyria, she's in Denver, hired by Blackfeet Oil to work in their corporate headquarters. In her first weeks there, wearing the correct, unfamiliar clothes provided by Grandma, she meets breezy officemate Maddie; gets cold-shouldered by most of her co-workers; has a one-night stand with irresistible executive Pete Tutaraitis; and witnesses two suicides falling from the 16th floor, which is occupied by oil company Love and Christiansen. Em soon discovers that Pete is married to Libby Hopkins, one of her Boston schoolmates. Both window jumpers--accountant Gerald Luftweiller, who worked at Love and Christiansen, and Scott Dinsmoore, with whom Em was to work on analysis of the Lost Coyote oil fieldwere from Boston, too. Even more startling is Sergeant Ortega's news that Scott's death was murder, not suicide. Em's overpowering need for answers soon has her working with, when not directing, the sergeant, as they slowly uncover a web of greed and chicanery, with undertones of even darker misdeeds. Too many emotional entanglements and too much psychobabble slow the pace, and some unlikely coincidences don't help, but Andrews's fine ear for regional speech and her feisty, dogged heroine provide a sporadically absorbing look at not-too-familiar territory.