Fire Sale — Sara Paretsky

A conscience can weigh a PI down more than the heaviest firearm--and get her into more trouble. It's that nagging conscience that makes V. I. Warshawski agree to fill in as coach for the girls' basketball team at her South Chicago alma mater--which in turn leads her to the headquarters of By-Smart, the global retail empire where V. I. hopes to get some desperately needed funds for the struggling squad. But conscience seems to be in short supply at By-Smart...with the exception of Billy Bysen, the earnest teenage grandson of the chain's gruff, tightfisted founder. And when Billy disappears--along with a mysterious document much desired by By-Smart's management team--V. I. is hurled onto a twisted, body-strewn path that runs through Chicago's dirtiest places and reveals some of its dirtiest secrets....