This is a result of the lies that he is surrounded by. Hamlet learns that Rosencrantz and Guildenstern have been spying on him as by order of King Claudius. These feelings of pain and sorrow become embedded deep inside Hamlet and they cause him to become excessively melancholic. Unfortunately, by the end of the play Hamlet seems to lose contact with his true, reflective self and gives in to his dark side. .
Hamlet's inner conflict, reflected in his delay in avenging Claudius for Lord Hamlet's murder, allows Claudius a great advantage of time to plot against him, and at the same time, creates external tensions that consequently lead to the unnecessary deaths of six innocent people. Hamlet thinks up the "Mouse-trap", a play about a King named Gonzago who is murdered the same way as Lord Hamlet was murdered. This was done to verify the truthfulness of the ghost by seeing the reaction of Claudius during the scene. Hamlet then searches for Claudius, ready to kill him. After learning the truth, Hamlet still procrastinates the killing of Claudius. Hamlet ponders, "Am I then revenged, to take him in the purging of his soul, where he is fit and seasoned for passage? No" (3.3 87-90). Hamlet does not realize that Claudius's attempts at prayer do not guarantee him fit for heaven. Hamlet does not want to send Claudius to heaven by killing Claudius while free of sins, despite the fact that Claudius would never go to Heaven in the first place. By leaving Claudius to live, Hamlet allows Claudius, who begins to realize that Hamlet knows the details of his father's murder, to plan against him. More importantly, Hamlet, in his angered state resulting from his encounter with Claudius, kills Polonius who was spying on Hamlet's conversation with Gertrude. This death has an immediate consequence. Claudius sends Rosencrantz and Guildenstern, his favorite spies who are next up to the throne, with letters for Hamlet's death with Hamlet to England.