SPOILER ALERT
This installment was a gruesome one. The villain was after Kevin Kerney for having shot him years earlier. However, only hints are provided through most of the story; and the killer is not known to Kevin until the very end and only then vaguely. He had killed an older woman by beating her with a hammer, and Kevin had shot him in the genitals, so he was unable to perform or have kids. When he concocts his well-developed plan to kill "everyone" he is focused on Kevin family. He also goes after the juvenile judge and the psych evaluator, and others that further his plan.
In the process of killing the people he leaves notes meant to predict future killings and to create fear for Kevin and Sara, whose son is to be born soon. He is cruel, killing animals: Kevin's horse by shooting him in the stomach, a painful way to die, which Kevin knows having been shot in the stomach himself. He leaves poisoned rats at Kevin's home and other sites. He kills a pet dog and beheads it, putting the body in one place and the head with another victim. He blows up Clayton and Grace's house. And there are other killings in gruesome methods that show him as a psychopath, with no conscience or feelings for his victims. He also cannot stop thinking about the joy he will get when he viciously kills their baby. It's a difficult read. Additionally, there are individuals who are collateral damage because of misunderstandings, miscommunications and the culture of militarized police...SWAT acting without regard for the mental health of the suspect. It will compel Kevin to begin a new training for his people.
Formally changing his name, with the intention of getting away with his revenge, Samuel Green, nee Richrd Finney picks an "unwitting beard", Noel Olsen, to take the fall, and he chooses unwisely. While Noel Olsen had been in prison for raping and killing a young woman with two friends, he comes out a reformed man from the sound of things. He plays great volleyball, and has a job, is a loner but not disliked. The only caveat...he dislikes gays. Probably because he was a white supremacist's "bitch" in prison. In the end Olsen's property yields five bodies of gay men he has killed over the five years he has been out of jail. They are found in cairns on the 85-acre parcel that he tells a neighbor he has no intention of selling to the government for a wildlife sanctuary, though it is a good deal, on land that is not worth anything. It is just another part of the disintegration of Green's plan. When Clayton Istee, Kevin's son and Apache policeman gets in the picture, he finds things that were missed in the original search of Olsen's property, and that refute the idea that Olsen has run.
Green sets up an elaborate set of evidence at a remote setting for the police to find, taking Olsen's body away so it appears he has run. But the vast investigation involving dozens of law enforcement individuals picks apart his plan. The process of Clayton involved in this case changes his mind about his father, and has his chewing of the long-term dislike that his mother has planted in his mind in doubt. His decision to go to see his new brother saves the day, when Green comes to kill Kevin and his family, by disguising himself as a flower delivery man; he is unaware that Clayton is there. Clayton shoots him.