At the beginning of the play, Horatio sees a ghost and proclaims that there is a sign that there will be an future attack in Denmark due to Prince Hamlet's father killing Prince Fortinbras's father. As the play starts, we learn that Prince Hamlet's uncle, Claudius, rules over the kingdom because Hamlet's father had passed away. The late King's wife, Queen Gertrude, was then forced to marry Claudius. As the new king, Claudius makes many changes. He doesn't let Hamlet continue his studies in Wittenberg, "granting the petition of young Laertes, son of the old counselor Polonius, to return to his studies in Paris;" (Grolier) and he sends representatives to Norway to stop the threat of the Prince. Since Hamlet cannot leave, he is forced to live in despair of what has happened. Horatio decides to show Hamlet the ghost he had seen. When they visit the ghost, it tells them to avenge his death by murdering his murderer, which is Claudius. Hamlet forces Horatio and the guard, that is with them, not to tell anyone of the things they saw. Before Laertes leaves he instructs his sister, Ophelia, to steer clear of Hamlet and to not trust him. As time goes on, Ophelia tells her father that Hamlet's actions towards her have been quite disturbing. Claudius sees Hamlet's change in attitude and sends for his friends, Rosencrantz and Guildenstern, to figure out what is bothering him. Hamlet soon discovers the purpose behind what Rosencrantz and Guildenstern are doing, they were helping the person who killed his father. Later Hamlet decides to put on a play in order to reveal Claudius's guilt and it doesn't work. As the play continues, Hamlet sees Claudius praying and he has the sudden impulse to murder him at that very moment. When Hamlet tells his mother of the ghost, she believes he has lost his mind. Claudius ends up sending Hamlet to England with Rosencrantz and Guildenstern. Hamlet then sends a letter to Claudius and Horatio of his returning home. Once Claudius hears this news he plans on murdering Hamlet using trickery. When Hamlet arrives, he tells Horatio how he knew of Claudius's plan to kill him while he was in England. Hamlet is then challenged to a duel by Laertes. As the match between Hamlet and Laertes begins, Claudius sets out a poisoned wine glass for Hamlet to drink and Gertrude ends up accidentally drinking it. After that, Laertes tells Hamlet of his and the King's trickery and Hamlet kills Claudius.