Crime exposes the dark places in the human heart, taking their measure, gauging their depths of cunning, desperation, passion or sheer malice. It measures, too, the criminal's urge sometimes childlike, sometimes supremely calculating - to act with impunity, to defy the social order and get away with it. Many of them have met their doubtful goal, but the perfect crime has its polar opposite: the crime so ill-conceived, botched in execution, or undone by bad luck that it looks pitiable against the ramparts of the social order. Between the two are a thousand shadings. Yet something essential in the nature of crime is defined by extremes of outcome - the law impotent against iniquity or the law rising triumphant above a blundering foe.