Revenge leads to madness when Hamlet avenges his father's death.
Hamlet Denies Ophelia
Hamlet denies ever loving Ophelia and berates her and women in general for their trickery and pretentiousness.
Ophelia Gone Mad
Ophelia sings about death and behaves erratically after her father has been killed.
Alas, Poor Yoric...
Hamlet encounters the skull of someone he once knew, and is disgusted by the fact that he knows someone who is buried in this grave.
Before dying Gertrude informs everyone that she was poisoned by King Claudius' wine. Before he dies, Laertes informs Hamlet that the sword tip that hurt him was poisoned by the King, and that he, Hamlet, is going to die as well.
Enraged, Hamlet stabs the king with the poisoned sword, then pours poisoned wine down the king's throat.
As Laertes dies he apologizes for his actions and asks for Hamlet's forgiveness.
A shot is heard without and Hamlet is informed that Fortinbras is crossing Denmark, coming back from his conquest over Poland.
Hamlet gives his approval to Fortibras to become king of Denmark after Hamlet's death, and he dies.