Drug runners have turned Artemis, Tex., across the Rio Grande from Mexico, into a war zone in Fields’s impressive debut, winner of the 2010 Tony Hillerman Prize. On both sides of the border, the police are outnumbered and whole neighborhoods fear the turf battles between the Medrano and the La Bestia cartels. Police chief Josie Gray and her small department are doing their best to keep the criminals in check, but losing ground every day. Josie is targeted after killing a La Bestia hit man and wounding another. She also learns she’s on the “enemies” list of a Second Amendment group, whose leader, Red Goff, has just been murdered. The town’s egotistical, power-hungry mayor constantly undermines her, and she finds evidence that at least one sheriff’s deputy is on the take. Fields’s rich plotting, nonstop action, and deft characterizations show the personal side of the larger issue of drug cartels on both sides of the border. (Nov.)