In Too Deep

Jack Reacher is a former major in the US Military Police who, since leaving the army, has drifted round the wide open spaces of America, hitchhiking or on buses, wherever the whim takes him. He has no permanent address, no job, no family ties, no car, no luggage, no mobile phone, no credit card - all he carries with him is a folding toothbrush.
Reacher is never looking for trouble, but somehow trouble always find him. He is the ultimate hero for our troubled times, with a keen moral compass and sense of justice, even if he is often prepared to take the law into his own hands: he says he doesn't want to put the world to rights, he just doesn't like people who put it to wrongs.