The novel is set in Paris in the late 19th century. The center of attention is the city's Opera, which was at the height of its glory during that period. In the underground of the magnificent building lies a secret. Torture chambers, hidden passages, labyrinthine corridors, subterranean lakes, and catacombs create a parallel world where the dark figure of Erik, the Phantom of the Opera, reigns. Erik, a deformed musician who oscillates between genius and madness, falls in love with the young soprano Christine. He becomes her teacher and protector, introducing her to the secrets of music and helping her to evolve into a great opera star. Her love for the viscount Raoul and her revulsion upon seeing his face ignite his jealousy and rage, leading him to abduct her. With the help of Persian, an old acquaintance of Erik's, Raoul will try to save his beloved and solve the mystery of the murder of his brother, who was found dead that same night.