Act 4 of Hamlet is a pivotal part of the play because it is in these scenes that Hamlet's fate is sealed. Claudius has been plotting against Hamlet since Act 3 because he was at first suspicious of Hamlet's crazy act and later he realizes that Hamlet knows the truth about Claudius's murder of King Hamlet. Claudius revealed himself with his behavior during the play within a play, and immediately after that, Claudius changed his initial plan to send Hamlet to England on business, to having Hamlet killed upon his arrival in England. Once Hamlet accidentally kills Polonius it is even more urgent that Claudius get rid of Hamlet because he is clearly proving that he will follow through with a plan of revenge. Luckily for him, Laertes shows up furious over the murder of his father and hungry for revenge of his own. Claudius uses this emotion and lack of good judgement to his advantage and plots the murder of Hamlet with Laertes. Together they devise the plan to host a fencing match but with sharpened and poisoned swords and a poisoned cup of wine. Laertes is so singled minded in his want for revenge that he doesn't question why Claudius is so willing to kill his nephew/step-son. When Laertes first storms into the castle he says "I will not be juggled with," but in a matter of minutes, Laertes is completely in the hands of Claudius. His desire for justice blinds him to the bigger picture. He only lives long enough to regret this plan and his part in it. His final words are to put the blame on Claudius and ask Hamlet for forgiveness. He foolishly put revenge ahead of common sense and logic.