"The Phantom of the Opera" is a novel by Gaston Leroux, first published in 1910. It tells the story of a mysterious figure known as the Phantom, who lives beneath the Paris Opera House. The Phantom is a talented composer and has a deep obsession with a young soprano named Christine Daaé. As Christine rises to fame, the Phantom's love turns into a dangerous obsession, leading to dramatic events at the opera. The story explores themes of love, beauty, and the struggle between appearance and reality, ultimately revealing the tragic nature of the Phantom's character.