Having recently lost his job as a history professor, David Mapstone returns to his boyhood home of Phoenix, Arizona, to find the city dramatically changed. It's now a haven for wealthy retirees and a seasonal retreat for West Coast ''sophisticates.'' But pockets of his earlier life - some welcome, some not - remain. Mapstone eagerly accepts a temporary job from his old friend and Maricopa County Chief Deputy Mike Peralta: Look into still-open cases and see if he can close any. He is beginning to settle into his new job when his college sweetheart appears at his door one evening. True to his memory of her, she is there because she wants something. Her sister is missing and she wants Mapstone to look for her. Mapstone's search for the missing woman is quickly resolved when her body is discovered in the desert, but he is stunned to find the dead sister in circumstances identical to a sensational 40-year-old unsolved murder. Mapstone's dogged investigation of both murders bridges the chasm of clashing cultures, meshing his own long-ago memories with the tangled doings of newcomers and their acolytes, young women eager to share the lifestyle of tainted wealth, drugs, and careless violence. Jon Talton is a fourth-generation Arizonan who grew up in the same Phoenix neighborhood David Mapstone calls home. Concrete Desert is first in the Mapstone series, followed by Camelback Falls, Dry Heat, Arizona Dreams and Cactus Heart. www.jontalton.com