"The best thing he ever wrote," observed Edmund Wilson of Thornton Wilder's National Book Award winner The Eighth Day (1967), an enthralling novel that shows Wilder revisiting the small-town America of Our Town to fashion a philosophical whodunit. A wrongful conviction for murder and a daring rescue lead to a meditation on justice, destiny, and "the impassioned will," for which "nothing is impossible." Wilder's last novel, the semi-autobiographical...