Toward the end of Francis Coppola's "Apocalypse Now," the camera casually, almost randomly, roams across a disheveled hut, passing a small number of scattered books lying in such a way as to suggest recent usage. One of these books is Sir James Frazer's "The Golden Bough." It is no accident. Indeed, this book holds the key to understanding the conclusion of the film that has baffled—and annoyed—most critics and will very likely be unsettling a number of moviegoers now that "Apocalypse Now" is entering general distribution….

If, as most critics have done, we look to Joseph Conrad's "Heart of Darkness" for the answer, we will be … disappointed. True, the film does rely upon Conrad's novella for its characters and plot structure, but still it does not explain Mr. Coppola's ending: In the book, Marlow, a young ship's captain, is hired by a rubber firm to guide...