"La Sonate à Kreutzer" (in English, "The Kreutzer Sonata") is a novella written by the Russian author Leo Tolstoy, known as Léon Tolstoï in French. This work is a powerful and controversial exploration of themes related to marriage, jealousy, and morality. The story is narrated by Pozdnyshev, who reflects on his failed marriage and the circumstances that led to the tragedy. The central focus of the novella is the intense jealousy Pozdnyshev feels, particularly regarding his wife's relationship with a violinist named Trukhachevsky and their performance of Beethoven's Kreutzer Sonata. Tolstoy delves deep into the psychological and emotional aspects of jealousy, love, and human nature. "La Sonate à Kreutzer" is celebrated for its exploration of morality, relationships, and the consequences of irrational jealousy.