Dom Casmurro is one of the most celebrated novels in world literature and a masterpiece of psychological fiction by Brazilian author Machado de Assis. Told through the reflective and deeply subjective voice of Bento Santiago-nicknamed "Dom Casmurro"-the novel explores memory, jealousy, love, and the unreliability of personal truth. As Bento recounts his youth, his intense love for Capitu, and the events surrounding their marriage, he becomes increasingly obsessed with the suspicion that Capitu betrayed him with his closest friend. Yet the novel never offers definitive proof, leaving readers to question whether the betrayal truly occurred or existed only within Bento's troubled mind. This ambiguity has made Dom Casmurro one of the most debated novels in literary history. Set in 19th-century Rio de Janeiro, the novel is both a social portrait of Brazilian elite society and a profound examination of human psychology. With subtle irony, elegant prose, and narrative innovation far ahead of its time, Dom Casmurro stands as a timeless study of doubt, obsession, and the fragile nature of truth.