Hamlet murders Polonius, accuses his mother, and sees the ghost again.
Characters: 
Gertrude

The queen attempts to speak with her son, but is frightened by his wild behavior and calls out for help.

Polonius

Polonius hides behind Gertrude’s curtain to eavesdrop, but calls out in fear after Gertrude does so. Hamlet hears him and stabs him through the curtain, killing him.

Hamlet

The prince angrily confronts his mother, and, hearing Polonius’s calls for help, mistakes him for Claudius and stabs him through the curtain.

Ghost

The mysterious figure from the first scenes of the play returns, reminding Hamlet of its desire for vengeance.

Scene Summary: 

In Gertrude’s private chambers, Polonius and the queen hear Hamlet approach. Polonius quickly hides behind a curtain, planning to eavesdrop on the conversation between mother and son. When Hamlet enters, he’s in such a rage that Gertrude cries for help. Hearing this, Polonius echoes her cries for help, revealing his hiding place in the process. Hamlet, thinking that Polonius is actually Claudius, stabs blindly through the curtain, killing Polonius on the spot. Instead of feeling any remorse, Hamlet turns on his mother, attacking her for marrying Claudius so soon after her husband’s death. In the middle of his tirade, the ghost makes an appearance to remind Hamlet of his real goal: vengeance. Gertrude, seeing Hamlet talk to a ghost that she herself can’t see, thinks he really has lost his mind. Hamlet threatens his mother and tells her that he knows Claudius is plotting against him, but that the king will get his just desserts in the end.