The Persian and Raoul overhear Erik and Christine in a room next to the torture chamber. Christine must decide whether she will marry Erik, as it is his dream to live amongst others with a wife. He has made a mask so lifelike that it would be possible, if only Christine will accept him. If she doesn't, he will kill everyone in the Opera at eleven o’clock the next day.

Erik leaves at the sound of a bell, and Raoul impulsively calls out to Christine. Christine can’t help them unlock the adjoining door because Erik has tied her up. When Erik returns, he declares the "siren" claimed another victim. Christine entreats Erik to untie her, playing on his love for her. As Erik sings a requiem for the dead man, Christine tries to steal the bag of keys.

Furious, Erik snatches the bag of keys back from Christine. She claims she is only curious about the torture chamber, but Erik sees through her trick. He illuminates the torture chamber and forces Christine to look through the viewing window. She lies that there is no one inside, but Erik still refuses to turn off the lights. With the lights on, the mirrors reflect an iron tree into an