Act IV, Scene vii:
Claudius convinces Laertes that he is innocent in Laertes' father's death and that Hamlet is to blame.
A messenger enters with Hamlet's letter and Claudius is amazed to find that Hamlet is still alive. Claudius reads the letter to Laertes. Hamlet is writing to inform the King that he has returned to Denmark and tha he wishes to meet with Claudius tomorrow.
Claudius, concerned about Hamlet's untimely return, advises Laertes to have a dueling match with Hamlet. In this match, Claudius plans to have Laertes kill Hamlet. They plan to cover the tip of Laertes's sword with poison.
Once Hamlet is struck with the sword, he will die. Hamlet's death will end Claudius' worries about anyone finding out about his involvement in his brother's death. To further ensure Hamlet's demise, Claudius intends to
present Hamlet, if he scores the first 'hit', with a poisoned goblet of wine. This way, Hamlet will be killed.
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