Alone on stage, Lady Macbeth expresses her unhappiness: there seems to be no end to her desire for power and she feels insecure and anxious.
Macbeth enters looking upset and she counsels him to stop mulling over the crimes they have committed.
But Macbeth declares that their job is not done: he still spends every waking moment in fear and every night embroiled in nightmares.
He even envies Duncan, who now sleeps peacefully in his grave.
Banquo states that he must ride in the afternoon but will return for the banquet.
Macbeth tells him that Malcolm and Donalbain will not confess to killing their father.
At this point Banquo's ghost appears unobserved and takes Macbeth's seat.
The guests urge Macbeth to sit and eat with them but Macbeth says that the table is full.
Just as the party resumes and Macbeth is offering a toast to Banquo, the ghost reappears.
As Macbeth once again bursts out in a speech directed at the ghost, Lady Macbeth tries to smooth things over with the guests.