"If it assume my noble father's person I'll speak to it though hell itself should gape and bid me hold my peace."
"The serpent that did sting thy fathers life now wears the crown."
"Oh my prophetic soul! My Uncle?"
"Fell into a sadness, then into a fast, Thence to a watch, thence into a weakness, Thence to a lightness, and, by this declension, Into the madness wherein now he raves And all we mourn for."
"Thoughts black, hands apt, drugs fit, and time agreeing, Confederate season, else no creature seeing, Thou mixture rank, of midnight weeds collected,"
While celebrating his mother Gertrude and uncle Cladius' marriage, Hamlet discovers his fathers ghost is haunting the castle.
After talking with his fathers ghost, he discovers it was his uncle who had killed his father and he seeks revenge.
"O, my offence is rank, it smells to heaven: It hath the primal eldest curse upon't A brother's murder."
Polonius tells the king and queen Hamlets madness is due to his love for Ophelia, his daughter. Claudius and Polonious plot to spy on Hamlet in order to be convinced that is why he is mad.
"O what a rash and bloody deed is this!"
Hamlet puts on a play in front of the court and the king that resembles the way his father was murdered. Claudius stops the performance early which proves his guilt.
Hamlet finds Caludius praying and confessing his sin of killing his brother. Hamlet was going to murder him but decides he needs to do so when Claudius isn't asking for forgiveness and is committing a sin.
Hamlet confesses to his mother that his madness has all been an act. While confessing to his mother he hears a noise thinking it is Claudius and kills him. But it was Polonius that was eavesdropping not Claudius.