ONE PERFECT SHOT

Undersheriff Bill Gastner of Posadas County, N.M., meets Estelle Reyes, the once-and-future undersheriff, in a welcome, well-wrought prequel.

The 18th entry in this sturdy series (Double Prey, 2011, etc.) begins with Gastner keeping the lid on a volatile population prone to impropriety, mostly homicide—a task that passed to Reyes eight novels ago, leaving Gastner to materialize from time to time as counselor, comforter and loving godfather to Reyes’ children. A 10-year trip to the past finds Gastner just as grizzled, potbellied, appreciative of a well-built burrito, and shrewd as a detective. Reyes, now 21, whom Gastner last saw when she was a tyke of 11, is the new department hire. Since she’s not Gastner’s choice, readers new to the franchise might well expect an outbreak of resentment. But Reyes proves irresistible: poised, respectful and extraordinarily pleasant to look at. She and Gastner click at once, a good thing indeed, since the freshly minted deputy has come on board just in time to help with a baffling murder case. Someone has fired a bullet into the middle of Larry Zipoli’s forehead while he was at work grading a county road, and the ballistics simply don’t add up. What unfolds is not so much a whodunit as a how-on-earth-did-it-get-done.

Gastner and Reyes charm from the get-go.