Scobie, a police officer in a flyblown West African colony during the War, is above suspicion. Then, passed over for promotion, he is forced to borrow money to send his faded wife Louise on holiday. In her absence he falls in love with a young widow, and, inexorably, his conscience and his love of God lead him to disaster. Greene explores some of the themes that most fascinated him in this atmospheric novel: the pull of the Catholic church, forbidden love and the impotence of goodness in an increasingly cynical and corrupt world.