The Kiss to the Leper by Francois Mauriac is a novel about a French priest named Charles who has become disillusioned with his life and the Church. After being sent to a leprosarium to care for leprosy patients, Charles gradually begins to see the beauty and dignity of these outcasts and rediscovers his own humanity and faith. Through his experiences with the patients and his interactions with a nurse named Marthe, Charles undergoes a spiritual transformation, becoming a more compassionate and selfless person. The book explores themes of faith, redemption, and the power of love.