Final answer:
Polonius dies in Act III, Scene IV of Hamlet when Hamlet mistakenly stabs him through a curtain. His death intensifies the tragic nature of the play and contributes to the unraveling of events.
Step-by-step explanation:
Polonius dies in Shakespeare's play Hamlet in Act III, Scene IV. During this scene, Hamlet mistakenly believes that King Claudius is behind the arras (a heavy curtain), and not knowing that Polonius is hiding there, he stabs through the curtain, killing Polonius. Polonius' death is fitting in the sense that it further intensifies the tragic nature of the play and contributes to the unraveling of events that ultimately lead to Hamlet's own downfall.