Hamlet visits Queen Gertrude's chamber and frightens her with sharp criticisms. Overhearing the argument from behind an arras (curtain), the spy Polonius worries for Gertrude's safety and calls out for help. Mistaking the concealed spy for King Claudius, Hamlet thrusts his sword through the arras and kills Polonius. Hamlet continues to chastise his shameful mother for marrying her beloved husband's foul brother. The ghost suddenly appears to Hamlet, dressed in a nightgown.
The phantom king reprimands Hamlet for slackening in his revenge. Queen Gertrude is horrified by Hamlet's mad behavior; because the Ghost is invisible to her, Gertrude believes Hamlet is conversing with the air. Hamlet instructs his mother to abstain from his uncle's incestuous bed. He discloses his actual sanity to his mother, and Gertrude vows to keep Hamlet's crafty madness a secret from Claudius. Aware of orders shipping him to England, Prince Hamlet senses a trap. He vows to distrust Rosencrantz and Guildenstern as he would distrust fanged snakes. The keen Prince lugs the body of Polonius into a neighboring room and bids his shaken mother goodnight.
