Polar City Blues — Katharine Kerr

Cashiered for mutiny by the Republic star fleet, Bobbie Lacey has made it her business to know everything that happens on the mean streets of Polar City. But something so big is going down, even she can't get all the answers.

An alien ambassador of the Confederation lies dead in front of City Hall, throat slashed by a deranged assassin. A mysterious alien artifact has been discovered in the slums of Porttown, a wildfire plague rages out of control, and the cops are stumped. If Lacey doesn't solve the mystery damn quick, her home turf will become ground zero in a shooting war between the Alliance and the Confederation.