The Phantom of the Opera (French: Le Fantôme de l'Opéra) is a novel by French writer Gaston Leroux. It was first published as a serialisation in Le Gaulois from September 23, 1909 to January 8, 1910. Initially, the story sold very poorly upon publication in book form and was even out of print several times during the twentieth century; it is overshadowed by the success of its various film and stage adaptations. The most notable of these were the 1925 film depiction, Ken Hill's 1976 musical at the Theatre Royal Stratford East followed ten years later by Andrew Lloyd Webber's 1986 musical that in turn inspired the 2004 film adaptation directed by Joel Schumacher.
The novel opens with a prologue in which Gaston Leroux claims that Erik, the "Phantom of the Opera", was a real person. We are then introduced to Christine Daaé who with her father, a famous fiddler, travelled all over Europe playing folk and religious music. Her father was known to be the best wedding-fiddler in the land. When Christine is six, her mother dies and her father is brought to rural France by a patron, Professor Valerius.
During Christine's childhood (which is described retrospectively in the early chapters of the book), her father tells her many stories featuring an "Angel of Music", who, like a muse, is the personification of musical inspiration. Christine meets and befriends the young Raoul, Viscount of Chagny, who also enjoys her father's many stories. One of Christine and Raoul's favourite stories is one of Little Lotte, a girl with golden hair and blue eyes who is visited by the Angel of Music and possesses a heavenly voice.
On his deathbed, Christine's father tells her that he will send the Angel of Music to her from Heaven. Christine now lives with Mamma Valerius, the elderly widow of her father's benefactor.
Christine is eventually given a position in the chorus at the Paris Opera House (Palais Garnier). Not long after she arrives there, she begins hearing a beautiful, unearthly voice which sings to her and speaks to her. She believes this must be the Angel of Music and asks him if he is. The Voice agrees and offers to teach her "a little bit of heaven's music". The Voice, however, belongs to Erik, a physically-deformed and mentally-disturbed charismatic genius who was one of the architects who took part in the construction of the opera and who secretly built a home for himself in the cellars. He has been extorting money from the Opera's management for many years. Unknown to Christine, at least at first, he falls in love with her.
With the help of the Voice, Christine triumphs at the gala on the night of the old managers' retirement. Her old childhood friend Raoul hears her and remembers his love for her. A time after the gala, the Paris Opera performs Faust, with the prima donna Carlotta playing the lead. In response to a refused surrender of Box Five to the Opera Ghost, Carlotta loses her voice and the Opera's grand chandelier plummets into the audience.
After the chandelier accident, Erik kidnaps Christine to his home in the cellars and reveals his true identity. He plans to keep her there only a few days, hoping she will come to love him, and Christine begins to find herself attracted to her abductor. But she causes Erik to change his plans when she unmasks him and, to the horror of both, beholds his face, which according to the book, resembles the face of a rotting corpse. Erik goes into a frenzy, stating she probably thinks his face is another mask, and whilst digging her fingers in to show it was really his face he shouts, "I am Don Juan Triumphant!" before crawling away, crying. Fearing that she will leave him, he decides to keep her with him forever, but when Christine requests release after two weeks, he agrees on condition that she wear his ring and be faithful to him.
Up on the roof of the Opera, Christine tells Raoul of Erik taking her to the cellars. Raoul promises to take Christine away where Erik can never find her and to take her even if she resists. Raoul tells Christine he shall act on his promise the following day, to which Christine agrees, but she pities Erik and will not go until she has sung for him one last time. Christine then realizes the ring has slipped off her finger and fallen into the streets somewhere, and begins to panic. The two leave. But neither is aware that Erik has been listening to their conversation or that it has driven him to jealous frenzy. During the week and that night, Erik has been terrorising anyone who stood in his way or in that of Christine's career, including the managers.
The following night, Erik kidnaps Christine during a production of Faust (by drugging the gas men and switching the lights off, he spirits Christine off the stage before anyone turned the lights on). Back in the cellars, Erik tries to force Christine into marriage. If she refuses he threatens to destroy the entire Opera using explosives he has planted in the cellars, killing them and everyone in the floors above. Christine continues to refuse, until she realizes that Raoul and an old acquaintance of Erik's known only as "The Persian", in an attempt to rescue her, have been trapped in Erik's hot torture chamber. To save them and the people above, Christine agrees to marry Erik. At first, Erik tries to drown Raoul and the Persian in the water used to douse the explosives, stating that Christine doesn't need another. But Christine begs and offers to be his "living bride", promising him not to kill herself after becoming his bride, as she had both contemplated and attempted earlier in the novel. Erik rescues the Persian and the young Raoul from his torture chamber thereafter. When Erik is alone with Christine, he lifts his mask a little to kiss her on the forehead, and Christine allows him to do this. Erik, who admits that he has never before in his life received or been allowed to give a kiss – not even from his own mother – is overcome with emotion. Christine gives him a kiss back. He lets Christine go and tells her "Go and marry the boy whenever you wish," explaining, "I know you love him". She leaves on the condition that when he dies she will come back and bury him.
Being an old acquaintance, The Persian is told of all these secrets by Erik himself, and upon his express request, the Persian advertises Erik's death in the newspaper about three weeks later. The cause of death is revealed to be a broken heart, and as promised, Christine returns to bury Erik and give his ring back to him.