At the beginning of act 3, scene 4, Macbeth demonstrates a calm and commanding presence toward his guests. He appears in control of the scene and even checks with the murderers to make sure Banquo is truly dead. His callous comments demonstrate a lack of remorse early in this scene:
‘Tis better thee without than he within. / Is he dispatched? (III.iv.16-17)
Yet Macbeth quickly loses control of the scene when Banquo's ghost appears at the banquet. This is a turning point for the remainder of the play as Macbeth seems to thereafter lose control of both his own sanity and the control he's previously exerted. At the feast, he grows increasingly paranoid toward the ghost, believing at first that it's a trick. His wife is forced to attempt to cover for his outbursts toward a guest that no one else can see or hear, but even she can only do so much.
Macbeth voices his guilt and his increasing sense of insanity as tension builds:
Ay, and since too, murders have been performed / Too terrible for the ear....
(The entire section contains 4 answers and 961 words.)