Early in Talton’s taut seventh David Mapstone mystery (after 2010’s South Phoenix Rules), a well-dressed man calling himself Felix Smith visits former historian and deputy sheriff Mapstone, now a PI, and his partner, former sheriff Mike Peralta, at their shabby Phoenix, Az., office. Smith pays them $10,000 in cash to investigate the apparent suicide of Grace Hunter, a former prostitute who went over a San Diego, Calif., condo’s 19th-floor balcony. Shortly after Smith leaves, Mapstone and Peralta hear gunfire. Outside, they find Smith with his face blown off in his parked car. Following their one lead, Mapstone and Peralta drive to San Diego, promoted as “America’s Finest City,” in search of Grace’s boyfriend, who they discover is in trouble with someone called AFP (“America’s Finest Pimp”). Succinct, wry descriptions of politics and the unwieldy development of Phoenix run alongside the fast-paced plot. While the end reveals rather cliché villains, the journey is thoroughly satisfying. (May)