The year is 1881, and the grand Paris Opera House is at the height of its fame. However, the theater hides a dark secret: it is haunted by an "Opera Ghost" who sends threatening letters to the managers, demanding a monthly salary and that Box 5 always be kept empty for his private use. In reality, the ghost is Erik, a brilliant architect, magician, and musical genius who was born with a face so horribly deformed it looks like a living skull. Shunned by society, Erik has built a secret, luxurious home next to an underground lake deep beneath the theater’s foundations.
Erik falls deeply in love with Christine Daaé, a young, innocent chorus singer whose father recently died. Speaking to her through the secret hollow walls of her dressing room, Erik disguises his voice and pretends to be the "Angel of Music" sent from heaven by her late father. For months, he gives her magnificent vocal lessons in secret, transforming her voice into something angelic and powerful.
Opportunity strikes when the Opera's leading soprano falls mysteriously ill, and Christine is chosen to take her place. Her performance is a triumph, capturing the heart of the entire audience, including Raoul, a wealthy young Nobleman and Christine’s childhood sweetheart. Raoul visits her dressing room to confess his love, which infuriates the listening Phantom. Driven by intense jealousy, Erik uses a secret mechanism behind her mirror to lure Christine deep into the dark, candlelit catacombs beneath the opera house.
Deep underground, Erik treats Christine with great gentleness, playing beautiful music for her, but he wears a dark silk mask over his face at all times. He warns her that she is safe as long as she never tries to look beneath the mask. However, overwhelmed by curiosity and fear, Christine waits until Erik is passionately playing his grand organ and pulls the mask off. She screams in horror as she sees his true face—a fleshless nose, sunken black eyes, and decaying yellow skin. Erik rages in agony, cursing his fate, but eventually calms down. He allows Christine to return to the surface world after she promises to wear his ring and remain faithful to his music, threatening to destroy the theater if she betrays him.
Terrified of the Phantom's growing madness, Christine meets Raoul secretly on the high, windy roof of the Opera House. She confesses everything to him—the underground lake, the terrifying skull face, and her fear of the voice in the walls. Raoul comforts her and they make a pact to flee Paris together the very next morning.
But they do not realize that Erik is hiding nearby, disguised as a stone gargoyle on the roof, overhearing every single word of their plan. Heartbroken and filled with a manic rage, the Phantom decides to take his final revenge. The next evening, during a live, crowded performance, the stage lights suddenly shatter into darkness. A terrifying scream echoes through the theater, and when the lights come back on, Christine has vanished into thin air, dragged down into the abyss right off the stage.
Raoul, guided by a mysterious man known as "The Persian," hunts for the secret passages leading into the catacombs. However, Erik traps them inside a horrific chamber of mirrors, a torture room that uses heat and illusions to drive prisoners to madness and suicide. Down in his home, Erik presents Christine with a terrible ultimatum. He points to two levers: one shaped like a bronze horse and one like a scorpion. If she turns the scorpion, she agrees to marry him. If she refuses, he will turn the horse, which will detonate tons of gunpowder hidden under the theater, blowing up the Opera House and killing thousands of innocent people above, including Raoul.
To save Raoul and the city, Christine makes a supreme sacrifice. She looks past Erik's terrifying face, cries out of pure pity for his lonely life, and kisses his forehead with genuine tenderness. This single act of pure, selfless love completely shatters Erik's cold heart. No one had ever kissed him, not even his own mother. Realizing that he cannot force someone to love him and that true love requires freedom, Erik begins to weep. He releases Raoul from the torture chamber, lets Christine leave with her lover, and begs her to return one last time after he dies to bury him. A few days later, the Phantom of the Opera dies quietly in his underground home from a broken heart, leaving behind a legendary mystery.