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 Scarlet Letter--made new for a disbelieving age.