Timothy Zahn, renowned for his bestselling Cobra and Black Collar series, and for his hugely successful Star Wars "TM" trilogy, takes a giant step with a novel sure to thrill science fiction readers everywhere.Mankind has colonized many planets, most under the control of Earth and its Pax Comitus. One group of colonies, the Empyrean, has resisted the Pax, and now the Pax has sent a spy, Kostas, to try to alter the balance of power there.Since the discovery of the black hole called Angelmass, the Empyrean has used "angels", particles emitted by the black hole, to keep their officials honest. Each official carries an "angel" held in a special containment field. A mysterious quality of these imprisoned particles makes it impossible for the bearer to act unethically.The Pax is sure that these "angels" must be part of an alien plot to subvert the Empyrean, and Kostas is sent to see what's going on. Kostas and a grifter named Chandris, who convinces him that she wants to help, though she's really after nothing but money, team up with a pair of angel hunters. The four become the focus of the conflict between the Pax and Empyrean, which culminates in a spectacular battle near Angelmass itself.