This is the 13th in John Sandford's Lucas Davenport "Prey" series. We are treated to a return of Clara Rinker, a hired killer who made her first appearance in Certain Prey. Sandford seems to like Rinker as a character, perhaps because crime and law enforcement tend to be a "boy's club" and the opportunity to write fully realized female characters is rare. In this case we see Rinker as a whole person - someone who was mostly doing a job, and attempting to get on with her life, when her boyfriend was murdered and her "baby" killed (she was pregnant). That leads her on a trail of revenge as she goes after the people responsible. As is standard for Sandford, the investigation is a series of long slow periods of drudge work with moments of wild action - just like real life. This is a book worth reading.