In Act I of Hamlet, the ghost of the king hamlet comes to the battlement, outside a castle in Denmark. Marcellus and Horatio ask the ghost to speak, but It remains silent. In Scene 2 the new king, King Claudius, King Hamlet's brother, is reprimanding Prince Hamlet for depressed. Claudius and Gertrude, Hamlet's mother, tell Hamlet to get over his father's death. Gertrude married Claudius one month after King Hamlet died. Marcellus joins Hamlet and tells him of his sightings.
In Scene 3 Laertes and his sister are saying goodbye, because Laertes is going to school in France. Ophelia, Laertes sister, is telling him that she is desperately in love with Hamlet. Laertes tells Ophelia that Hamlet will just use her for sex. Laertes makes Ophelia promise that she will not see Hamlet.
In Scene 4 Prince Hamlet goes to see if what Marcellus is telling him is true. Sure enough it is. The ghost beckons Hamlet to follow him; and then he talks to him. The ghost tells him that Claudius killed him by putting poison in his ear. The ghost wants Hamlet to bring Claudius revenge. In the last scene, the ghost tells Hamlet that it is not Gertrude fault that he has died.
He thinks that Claudius has brainwashed her.