When an old woman falls down her cellar stairs, breaks her neck, and dies, it's the sort of accident you expect, and you write it up that way and go on to the next problem afflicting the sheriff's department in a rural county with a small population. Except Undersheriff Bill Gastner of the Posadas County, NM Sheriff's Department realizes that someone's cleaned up the scene afterward, and it is very likely to be murder, not an accident.
When you mix in an old Mexican whose mind is failing, the poisoning of the man's dogs, the murder of a local real estate broker on the Mexican's property, and a missing teenager, suddenly the small sheriff's department needs to be umpteen places at once. With - as it turns out - two murders to deal with, a murderer who doesn't particularly care who he hurts or kills, and a mother whose concern for her son is minimal at best, Gastner, Det. Estelle Reyes-Guzman, Sheriff Martin Holman, and the rest of the department have more than enough work to do.
As always the police procedure and the depiction of Posadas County are the strongest parts of the book, though the characterizations come in right up there. The Posadas County landscape becomes a character in its own right - an empty, varied place with mesas and rocks and plains and mountains, where criminals think they can get away with anything, and would too, if it weren't for Gastner and company.