"J.R. Moehringer grew up listening for a voice: the sound of his missing father, a disc jockey who disappeared before J.R. spoke his first words. As a boy, he would press his ear to a radio, straining to hear the keys to his own identity. His mother was his world, his anchor, but he needed something else, something he couldn't name. So he turned to the bar on the corner, a grand old New York saloon that was a sanctuary for all types of men--cops and...