Someone's killing Reacher's buddies. Nine members of a team of elite ex-army cops - good enough to go to Atlanta and come back with the Coke recipe according to Reacher. Now at least one of them is dead.
Someone makes a deposit into Reacher's dwindling bank account. An irregular figure. Reacher finds out when he checks his balance from Portland and realizes its a code for help; he traces it to one of the team - Chicago based Frances Neagley. Reacher then finds out that Calvin Franz from their team has been killed - legs broken and thrown out of a helicopter into the desert. Calvin's office has been searched and ransacked by the killers but he had a secure system of backing up his files by using the United States Postal Service. Reacher and Neagley find his backup files and get to work on figuring out the password. They also visit the last employer of another team member who's missing - Tony Swan - a large defence contractor who'd let go of Swan a few weeks back.
Soon enough Reacher and Neagley are joined by David O'Donnell and Karla Dixon - and they move forward as a team. They trace their team members careers through Las Vegas casinos, manage the bureaucracy of the Department of Defense, negotiate the opaque world of defense contracting and unravel a terrorist plot. On the way another (undercover) cop gets thrashed, and the team is used as bait by the police. Reacher is seen interacting in and being part of a team in which he is an equal participant, rather than the primary protagonist. The team has its own idiosyncrasies - one of them cannot handle affectionate physical contact, another is a dapper, organisational expert who carries a ceramic switchblade to hoodwink the metal detectors at the airport; each one could have their own novel length origin story.
Along with his folding toothbrush Reacher begins carrying his passport since the events of 9-11, but draws the line at keeping a spare shirt. In his own words its a slippery slope from the extra shirt to having a house, car, savings plan and filling out all kinds of forms. Also in attendance is more weird maths requiring Reachers intellectual leaps of guesswork, factoids about the naming of Molotov cocktails and the practice of maxalding while tied up. After catching up with his former colleagues and seeing their varied career paths Reacher questions his perpetually untraceable status but eventually gets on a bus with no idea where its heading.