As Roger Lambert tells it, he, a middle-aged professor of divinity, is buttonholed in his office by Dale Kohler, an earnest young computer scientist who believes that quantifiable evidence of God's existence is irresistibly accumulating. The theological-scientific debate that ensues, and the wicked strategies that Roger employs to disembarrass Dale of his faith, form the substance of this novel—these and the current of erotic attraction that pulls Esther, Roger's much younger wife, away from him and into Dale's bed. The novel, a majestic allegory of faith and reason, ends also as a black comedy of revenge, for this is Roger's version—Roger Chillingworth's side of the triangle described by Hawthorne's <i>Scarlet Letter</i>—made new for a disbelieving age.