The Shape Shifter by Tony Hillerman
Call Number: MYSTERY HILLERMA
Since his retirement from the Navajo Tribal Police, Joe Leaphorn has been called on occasionally by his former colleagues to help them solve a puzzling crime. And Leaphorn, aided by Jim Chee and Bernie Manuelito, always delivers. But this time, the problem is with an old case of Joe's -- his "last case," unsolved and haunting him. And with Chee and Bernie on their honeymoon, Leaphorn is on his own. The case involved a priceless Navajo rug gone missing. Now, years later, Leaphorn is picking up the threads of a crime he'd thought impossible to solve.