Hamlet, son of the late King Hamlet (Senior) and Gertrude, is a philosophy student at the University of Wittenberg in Germany. After his father’s sudden death, he quits school and returns to Denmark. That his mother, Gertrude, rushed to marry Claudius, his uncle and brother of Hamlet Senior - made Hamlet feel betrayed and angry.
One night the ghost of his dead father appears to him, accusing Claudius of killing him by dripping poison into his ear." If thou didst ever thy dear father love— Revenge his foul and most unnatural murder!" the ghost commands to appalled Hamlet.
Hamlet swears to take revenge quickly - but then things get complicated and the revenge is delayed...