Without Fail (Lee Child)

Jack Reacher walks alone. No job, no ID, no last known address. But he never turns down a plea for help. Now a woman tracks him down, because she needs a hand with her new job. Her task? Protecting the Vice President of the United States from someone threatening to kill him. And so Reacher, with nothing but his toothbrush and the clothes he stands up in, enters a very exclusive club at the very heart of Washington power: the offices of the United States Secret Service. Here, he must literally put himself in the line of fire, pitting his native cunning, surly charm and instinctive but controlled violence against the wiliness of bureaucrats and the ghosts from his own past - as well as the brutal ruthlessness of the mystery assassin.