This is the fourth book in Tony Hillerman's masterpiece "Navajo Detectives" series and one of the best of the whole series. In the first three books Lt. Joe Leaphorn is the main character. "People of Darkness" introduces Sgt. Jim Chee, a younger and more complex man who is torn between the white man's world - and a career in the FBI - and the Navajo way as a "singer" or shaman. Also introduced in this book is an appealing, peaches-and-cream Wisconsin girl, Mary Landon, as a mild love interest for Chee.
A bomb goes off in a hospital parking lot, apparently aimed at killing a man who is already dying of cancer, a box containing little of apparent value disappears from a rich man's house, and an oil well explosion thirty years back has some connection to these events. This is vintage Hillerman: a story than ranges over vast areas of time and space. The villain in "People of Darkness" is one of Hillerman's best: a cold professional with the vulnerability of a battered child.
Hillerman's strengths are authenticity and atmosphere. Elements of Navajo culture, religion, and folkways are woven into the fabric of his novels. His landscapes are harsh and spectacular. Nature is magnificent, but also menacing. In this exotic setting, the supernatural seems almost possible and little chilly fingers tickle your spine. If you are an urbanite, you may not like Hillerman; but if you are drawn to big, blank spots on the map you will likely love him. Not the least of his accomplishments is that he has probably taught more people about the Navajo -- and generated more interest in Navajo culture -- than any other writer.