Burn marks - Sara Paretsky

When her seedy and importunate Aunt Elena turns up on her doorstep at midnight, having been burned out of her old people's home, V.I. Warshawski is exasperated rather than curious. Her interest is aroused only when an old friend, now a rising politician, puts pressure on her not to investigate ... and what she discovers isn't pretty: massive corruption and collusion among Chicago politicians and the construction industry. In the complex threads of past loyalties and big aspirations, the political stakes are high and friendship is cheap.