The sixth Jack Reacher novel opens when a woman named M. E. Froelich, who is the Secret Service agent in charge of security for Vice President-Elect Brook Armstrong, asks Reacher to assassinate Armstrong--in theory, of course. Someone has been sending death threats to Armstrong, which have been intercepted by the Secret Service, and Froelich wants Reacher to test the security arrangements that they have designed for the VP-Elect.
Reacher recruits his ex-army sergeant Frances Neagley, and together they demonstrate that a determined, skilled assassin could easily get through the safety net that the Service has erected around Armstrong and kill him with no trouble at all. Properly chagrined, Froelich and her boss then hire Reacher and Neagley to help protect Armstrong and track down the potential assassins.
Reacher's task is complicated by the fact that Froelich was the ex-lover of Reacher's brother, Joe. As readers of the series will remember, Joe Reacher, who worked in the Treasury Department, was killed at the very beginning of the series. Froelich still has unresolved feelings for Joe--she still has his suits hanging in her closet--and some of these feelings may be transferred to Jack.
It's quickly apparent that the would-be assassins are clever and resourceful and that they may be more than a match for Reacher, even with Neagley's help and that of the entire Secret Service. It's a chess match on a large scale, and one that moves like a rocket. There are a lot of great scenes in the book that keep the reader turning the pages rapidly, and it covers a lot of ground, geographically and otherwise. All in all, this may be one of the best books in this series.