Before he became a private investigator, before he served in the Detroit police, and long before he retreated to the wintry reaches of Michigan's Upper Peninsula, Alex McKnight played ball in the minor leagues. He doesn't spend much time thinking about those days, at least not until a former teammate comes looking for him. . . . The man's here to ask a favor. He wants Alex to help him find the woman with whom he had a brief, passionate affair three...