The Banquet Scene: Guilt Takes Over
You're watching Macbeth completely lose it at his own banquet - he's seeing Banquo's ghost and freaking out in front of all his guests. This moment is massive because it shows what ambition has actually cost him: his sanity.
When Macbeth says the sight might "appal the devil," Shakespeare is being clever here. Macbeth might actually be talking about himself as the devil - he's so horrified by what he's become that even he can't handle it. The guilt from murdering Banquo is literally haunting him.
Lady Macbeth's reaction tells us everything. She dismisses his fear as just an "air-drawn dagger" - basically calling it all in his head. Her use of the word "flaws" suggests she thinks his guilt is a weakness that needs fixing, which shows how twisted their relationship has become.
Key Point: This scene proves that Macbeth's ambition hasn't brought him power - it's brought him terror and isolation.
