This book is about the Hegemony police force in the Tiamat capital city of Carbuncle. This police force is charged with keeping dangerous galactic technology out of Tiamatan hands, as well as other more traditional police duties. Nyx LaisTree is a young policeman from the planet Newhaven. On the night of his nameday he and his brother participate in an illegal raid on a warehouse which is a conduit for passing illegal tech to the Tiamatans. But something goes horribly wrong, and almost all the raiders, including Nyx' brother, are killed, leaving only Nyx alive.

Upon his recovery, LaisTree realizes that his superiors are after something they think he knows about the raid, but he can't remember anything. Before long, the stiff Police Sergeant BZ Gundhalinu (a major character in the original trilogy) is involved, and so is a "whore with a heart of gold" -- a Tiamatan named Devony Seaward. Devony is a spy for the Snow Queen, but she finds herself falling for LaisTree. Soon the three of them, unsure if they can even trust each other, are forced into an alliance against unknown enemies -- possibly even higher-ups in the Police force, but certainly underworld figures controlled by the mysterious man called the Source. And into the mix steps the offworld woman Mundilfoere, who seems to want the same thing the Snow Queen wants, and LaisTree's superiors want, and the Source wants.

All plays out in a fast-moving and enjoyable fashion. The story is a good read, though its reliance on coincidence and such clichés as Devony and LaisTree falling instantly in love make it a bit contrived at times. Also, the whole thing is somewhat uneasily shoehorned into the existing structure of the trilogy. This turns out to be a story about something that gains great importance in The Summer Queen, but that importance is not clear to anyone who reads only this book. Which is to say, the mystery here is something of a McGuffin chase, absent knowledge of the events of The Summer Queen. At the same time, this book's use of, in particular, Gundhalinu and Mundilfoere, major characters in The Summer Queen, constrains both the author's choices and the reader's expectations (for those who have read the earlier book). In summary, I'd rate this as enjoyable light reading, an interesting addition to a fine series, but not an essential book.