In a little Mississippi town, three women have been murdered, and Reacher's sent by the army to work undercover and see what he can find out. Why? Because there's an army base nearby and because a senator's son is also on the base. Reacher's cover is blown about five minutes after he gets to town, and he begins to investigate the murders, though that's not his job. He and the local sheriff, a very attractive woman, begin an affair. (There's a good bit of softporn sex in this book, more than in the earlier Reacher novels, as I recall.) Strange things are going on around the army base. Bad things happen. Before long, even the sheriff is a suspect.
Reacher, of course, sorts it all out in his usual fashion. Due process? Reacher laughs at due process. He takes care of things his own way.
The clock in Reacher's head, the one that's accurate to the minute, if not the second, is mentioned several times. There's a funny line where Reacher says he doesn't know anything about fruit trees. If so, it's the only thing he doesn't know about, as he spouts plenty of knowledge before the end of the novel.
The book's fast and entertaining, sure to make Reacher fans happy and to capture a few new ones.