Hamlet’s father, the King of Denmark, dies suddenly, and his throne has been taken by the dead King’s brother Claudius, who immediately marries Gertrude the dead King’s widow. Hamlet suspects that his father was murdered by Claudius and Gertrude and his suspicion is strengthened by the news that his father’s ghost has been seen haunting the Castle of Elsinore. One night, on the castle battlements, the ghost reveals that he was indeed murdered, and makes Hamlet swear to avenge him.