Hamlet stops and tells the ghost he will go no further.  The ghost turns to Hamlet and instructs him to listen, as there isn't much time to talk.  The ghost tells Hamlet that he is the spirit of his dead father.  He is doomed to walk the earth at night and burn in hell by day.  He demands that if his son loves him, he avenge his murder.  The Prince pleads with his father to tell him who committed the crime so that he may seek revenge.  The late King says that the crime had been committed by his brother Claudius, having won over the affections of the Queen, to obtain the crown.  Claudius had slipped into the palace garden and poured poison into the ears of the sleeping king.  Then, he passed the death off as being caused by a snakebite.  The late King tells his son to seek revenge against Claudius but to leave his mother to face her punishment in the afterlife.  The ghost exits and Hamlet swears revenge.  Horatio and Marcellus arrive and Hamlet swears them to secrecy along with the disembodied voice of the ghost.  Horatio and Marcellus swear the oath and the three men exit. 

Polonius sends his servant Reynaldo to Paris to question Laertes' friends and acquaintances in order to discover how his son is living.  He wants to be sure that Laertes hasn’t returned to the wild, youthful behavior that marked his past.  Ophelia enters to tell her father of a visit from Hamlet. She is concerned because he was disheveled, pale, and acting quite mad.  Polonius fears that Hamlet is mad for her love and upon learning that his daughter has obeyed in avoiding the Prince, becomes convinced.  Polonius takes Ophelia and rushes off to tell the King.

Claudius has summoned Rosencrantz and Guildenstern, two boyhood friends of Hamlet.  He and Queen Gertrude feel that they can discover the cause of the Prince's apparent madness and send them to spy on him.  They leave and Polonius enters.  He reports that the ambassadors, sent to Norway, have returned and that he has discovered the cause of Hamlet's madness.  He leaves to retrieve the ambassadors and Gertrude expresses doubt that the madness is caused by anything other than King Hamlet's death and the hasty marriage that followed.  Polonius returns with Cornelius and Voltemand who report that they have been successful in stopping the attack of Fortinbras.  The ambassadors leave.  Polonius informs the King and Queen that Hamlet's madness is for the love of his daughter Ophelia, offering as evidence a poem written by the Prince.  He bets his life and office on this.  Polonius suggests that they send Ophelia to talk to Hamlet while they spy on him.  The King agrees and Hamlet enters reading a book.  Polonius asks to be left alone with the Prince and the King and Queen exit.  Polonius attempts to talk with Hamlet and comes to believe there to be some sort of method to his madness but cannot discover it.  He decides to leave and send in Ophelia.  Guildenstern and Rosencrantz enter as he leaves.  Hamlet instantly recognizes that they were sent by Claudius and tells them.  They admit it and Hamlet tells them of his depressed behavior.  They tell him that an acting troupe is on its way to entertain him.  He tells his friends that he is not entirely mad…only in certain situations.  Polonius enters announcing the arrival of the players.  Hamlet compares him to Jephthah, a biblical character who unintentionally sacrifices his daughter (Judges 11: 29-40).  The players enter and Hamlet persuades them to perform a speech.  He then arranges to write a speech to insert in the play they will perform the next night.  Afterward, he is filled with shame that the actor had shown more passion in his performance than he had shown thus far in avenging his father.  He hopes that the speech writes will inspire a guilty reaction from his uncle so he may see proof of the crime. 

Rosencrantz and Guildenstern report that they have failed to discover the cause of Hamlet’s madness.  They tell Claudius and Gertrude that the Prince showed signs of joy regarding the upcoming performance.  Polonius confirms this, further saying that Hamlet would like the King and Queen to attend.  Next, Claudius instructs Ophelia to meet with Hamlet so that it may be observed whether or not his madness is caused by love.  Polonius and Claudius then follow Ophelia as she wanders out to be met by Hamlet.  Hamlet is initially kind but then turns on her.  He denies having ever loved her and tells her to enter a nunnery.  He calls her father a fool and insults womankind before exiting.  Ophelia is crushed and he King quickly denounces the idea of Hamlet’s madness being caused by love.  Claudius decides to immediately send the Prince to England as an Ambassador in order to clear out the cause of his madness but Polonius convinces him to wait until the Queen is able to talk with Hamlet alone. 

Hamlet instructs the players on how to perform.  As he is finishing, Polonius, Rosencrantz, and Guildenstern enter to tell him that the King and Queen are on their way to attend the performance.  Horatio enters and Hamlet reminds him of the ghost and secures his help in observing Claudius during the performance for signs of guilt.  The King, Queen, Polonius, Ophelia, and the rest of the court enter for the performance.  Hamlet makes comments to Ophelia for all to hear regarding his mother’s hasty marriage.  The players begin with the dumb (without words) show, which depicts a scene identical to the murder of King Hamlet.  Ophelia attempts to elicit the meaning of the dumb show from Hamlet but he will not tell.  The play begins.  Hamlet tells the King and Queen that it is the depiction of a murder in Vienna and narrates as the players continue.  As the murder of the actor king in the garden is enacted, Claudius jumps up, stops the play, and runs out.  Hamlet takes this action as proof of his guilt.  Rosencrantz and Guildenstern arrive to inform him that his mother desires to speak with him.  Polonius enters as they talk and repeats Gertrude’s desire.  Hamlet sends them to tell her that he is coming.  He plans to give his mother a harsh talking to.