 The play opens with Hamlet deeply depressed over the recent death of his father, King Hamlet, and his uncle Claudius' ascension to the throne and hasty marriage to Hamlet's mother Gertrude.One night, his father's ghost appears to him and tells him that Claudius murdered him in order to usurp the throne, and commands his son to avenge his death.Claudius sends for two of Hamlet's friends from Wittenberg, to find out what is causing Hamlet so much pain.