Hamlet intends to make his mother see the truth, to call her to task for her marriage to his uncle, the death of his father, and her complacency amidst the violence. Gertrude believes he wants to murder her, but his intent is to expose her to herself. Hamlet presents Gertrude with two portraits, one of her first husband and the other of Claudius. He describes the two as opposites, the one all nobility and virtue, the other all deformity and vice. Gertrude is deeply affected by this comparison and seems to comprehend the enormity of her sin. Hamlet continues to berate her and describe Claudius in the most foul and hurtful language. While in the middle of this harangue, Old Hamlet’s ghost appears once more, telling Hamlet to stop torturing his mother and to remember his duty to kill Claudius. At the ghost’s command, Hamlet consoles his mother. Gertrude, unable to see the ghost, sees Hamlet talking to thin air and resolves that he is indeed insane. The ghost exits.
Hamlet's words to his mother are cruel and accusatory:
“Nay, but to live / In the rank sweat of an enseamed bed, / Stewed in corruption, honeying and making love / Over the nasty sty.”