As a boy, Stephen J. Dubner's hero was Franco Harris, the famed and mysterious running back for the Pittsburgh Steelers. When Dubner's father died, he became obsessed--he dreamed of his hero every night; he signed his school papers "Franco Dubner." Though they never met, it was Franco Harris who shepherded Dubner through a fatherless boyhood. Years later, Dubner journeys to meet his hero, certain that Harris will embrace him. And he is . . . well,...