Karen had been driving, with the heater turned way up, nearly all night. She’d forgotten how cold the desert can be at this time of year. The warmed scent of Yucca, Saguaro, and Sage pushed in through the Toyota’s dashboard vents. In the back seat, almost invisible in the car’s tunnel-dark interior, her small suitcase, pile of manila file folders, and tiny black PDA, were slumped over in a mound,…