Book excerpt: A science fiction mystery with a political twist. The investigation of blackmail and murder on two planets uncovers an interstellar plot that jeopardizes the political balance between the human dominated Republic and the two major alien dominated governments. Set both in Polar City on Hagar and on the capital planet of Sarah POLAR CITY NIGHTMARE explores the universe of katharine Kerr's previous bestseller, POLAR CITY BLUES, digs into its history, and takes a closer look at the interstellar confederation, one of its major cultures. It develops themes first sounded in the original book: machine intelligence, prejudice, and human relationships, along with a look at what is truly 'alien'. It is a major work of SF imagination.