Hamlet’s father dies and his mother marries his uncle, leaving Hamlet very depressed and contemplating suicide. The dead king starts visiting the castle to ask him to avenge his death. Hamlet now has two problems; he has to find out if the ghost was telling the truth and to kill his father’s murderer. This is the main theme of the tragedy, a more resolute hero, would have killed his uncle first, and asked questions later.
Hamlet pretends to have gone mad to get his proof without his purpose being detected. He mistrusts everyone except his good friend Horatio. He mistreats his mother, not knowing whether she knows she has married her late husband’s killer, he mistreats Ophelia, for she is the daughter of the Lord Chamberlain, Polonius and he definitely mistreats Polonius himself. During Hamlet’s quest for the truth, everybody dies: Ophelia goes insane with his rejection and drowns in the river, Polonius is killed by him while trying to eavesdrop on a conversation between Hamlet and his mother, and the rest of the characters are (like old King Hamlet) killed by poison, including Hamlet himself.