You DO NOT MESS with the Special Investigators!
The events of 9/11 changed Jack Reacher's drifter life in a practical way. In addition to his folding toothbrush, he now needs to carry photo ID to get around. Yet he is still as close to untraceable as a human being in America can get.
So when a member of his old Army unit manages to get a message to him, he knows it has to be deadly serious. The Special Investigators always watched each other's backs. Now Reacher must put the old unit back together. Someone has killed one of them, and he can't let that go.