"The Phantom of the Opera" by Gaston Leroux is a Gothic horror novel first published in 1909-1910. Set beneath the grand Paris Opera House, the story follows a mysterious, disfigured figure known as the Phantom who haunts the theater's depths. When he becomes obsessed with a young soprano named Christine Daaé, a dangerous love triangle emerges involving her childhood friend Raoul. As the Phantom's demands grow more violent and his jealousy intensifies, Christine finds herself trapped between two worlds—one above ground, one in the shadows below.