Carlotta thinks she will sabotage the superlatively-talented Christine, but she is really setting herself up to become a target for the Phantom's anger. In Chapter 8, when Erik becomes displeased by Carlotta's emotionless voice, he completely ruins her performance:
No one could have predicted anything like this. Carlotta was still unable to believe what her throat and her ears had told her. The crack of a thunderbolt would not have startled her as much as that hoarse croak springing out of her mouth; and thunder would not have caused her downfall. Whereas a toad crouched on a singer’s tongue will inevitably ruin her. Some have even died from it.
The narrator describes her downfall in dramatic terms, comparing the shock of her voice to that of a thunderbolt. This is an example of dramatic irony because the reader is clued in to expect her downfall even before this scene, but Carlotta continues to believe she will succeed in sabotaging Christine. As the narrator puts it, "no one could have predicted" this course of events; that is, no one in the story could have predicted it. But readers have many context clues throughout the preceding chapters, as well as an intuition about what the music-obsessed Phantom might do to someone who sings poorly yet tries to compete with his beloved Christine.
Erik resents his compulsory mask-wearing, but he is far less masked than the other metaphorically-masked characters. One example of masked feelings includes Christine's bogus engagement to Raoul. In Chapter 12, Christine suggests a "secret marriage" that will last only one month:
"But if we cannot be married, we can become engaged! No one but us will know. There have been plenty of secret marriages! Why not a secret betrothal? Let us become engaged, Raoul, for a month! In a month’s time, you will sail away and the memory of that month will keep me happy for the rest of my days!" She was overjoyed by this prospect. Then she became serious again and added: "This happiness will hurt no one."
Here, Christine claims that the mere memory of their month-long engagement will keep her happy for the rest of her life. Her invention of a bogus union is her attempt to mask the unhappy confusion of being trapped by the Phantom. She and Raoul merely "play" at being husband-and-wife-to-be in a "beautiful game" that serves to cover her sadness for a little while.
Other examples of metaphorical masking include Christine and Raoul's many attempts to deceive Erik and the Persian's lies about why he comes to the opera. By contrast, Erik's mask eventually comes off, leaving him vulnerable to Christine, who receives him with unexpected warmth. This decision to unmask makes Erik the least hidden and most vulnerable character in the book. Masks appear as a significant metaphor for the hiddenness of identity and motive; the irony of Erik's compulsory mask emerges as the other characters' tendencies to mask their true desires or feelings become apparent. Throughout the story, this irony depends on the device of masking as an extended metaphor for concealment.
Ironically, Erik's conduct (not his appearance) causes people to hate and fear him. He believes that his face scares people above anything else, but his behavior is what scares them. This becomes clear as Christine talks about her fear of his acts of "insane love" even as she is able to show sympathy for Erik's extreme physical imperfection. For example, in Chapter 27, Christine is able to look beyond Erik's disfigured face and recognize his humanity:
I [Erik] tore off my mask so as not to lose one of those falling tears … and she did not turn away! She did not die! She stood there, weeping over me, weeping with me. We cried together! Almighty God, you have granted me all the happiness a man could ever wish for!
Here, Christine does not turn away from Erik. Instead, she takes his hand and kisses him on the forehead. Her physical gestures and weeping over Erik show that she does not fear him for his face. She calls him "poor unhappy Erik" and displays great sympathy.
Throughout the story, though, Christine remains in constant terror of his power over her. The Phantom's violent actions often frighten Christine, and in Chapter 13 she admits that the main reason that she obeys his commands is not out of respect or admiration, but rather out of fear:
Believe me when I say that with each of my visits to Erik my horror of him has grown; for, instead of calming him, as I hoped, each of those visits only served to heighten his insane love! And I am afraid of him, so very afraid!
If Christine were afraid of the Phantom's appearance, then her first visit would have been the worst. However, her visits get progressively more terrifying as his behavior devolves into madness. This is ironic because readers would expect Erik's appearance to elicit hatred and fear, but it's actually his behavior that has this effect.
Ironically, Erik's conduct (not his appearance) causes people to hate and fear him. He believes that his face scares people above anything else, but his behavior is what scares them. This becomes clear as Christine talks about her fear of his acts of "insane love" even as she is able to show sympathy for Erik's extreme physical imperfection. For example, in Chapter 27, Christine is able to look beyond Erik's disfigured face and recognize his humanity:
I [Erik] tore off my mask so as not to lose one of those falling tears … and she did not turn away! She did not die! She stood there, weeping over me, weeping with me. We cried together! Almighty God, you have granted me all the happiness a man could ever wish for!
Here, Christine does not turn away from Erik. Instead, she takes his hand and kisses him on the forehead. Her physical gestures and weeping over Erik show that she does not fear him for his face. She calls him "poor unhappy Erik" and displays great sympathy.
Throughout the story, though, Christine remains in constant terror of his power over her. The Phantom's violent actions often frighten Christine, and in Chapter 13 she admits that the main reason that she obeys his commands is not out of respect or admiration, but rather out of fear:
Believe me when I say that with each of my visits to Erik my horror of him has grown; for, instead of calming him, as I hoped, each of those visits only served to heighten his insane love! And I am afraid of him, so very afraid!
If Christine were afraid of the Phantom's appearance, then her first visit would have been the worst. However, her visits get progressively more terrifying as his behavior devolves into madness. This is ironic because readers would expect Erik's appearance to elicit hatred and fear, but it's actually his behavior that has this effect.
