On January 7, 1980, in the run-up to the publication of his landmark bestseller Thy Neighbor's Wife , Gay Talese received an anonymous letter from a man in Colorado. "Since learning of your long awaited study of coast-to-coast sex in America," the letter began, "I feel I have important information that I could contribute to its contents or to contents of a future book." The man went on to tell Talese an astonishing secret, that he had bought a motel...