King Hamlet's ghost, despite having died before the play began, was the driving influence of the plot as he was the one who said to Hamlet “Avenge his disgusting and utterly unnatural murder” (1.5.24-5). Hamlet's grief, his mother's betrayal, the appearance of his father's ghost, and the discovery of his father's murder all contribute to Hamlet's fall into madness, misery, and his role as a tragic hero, Brutus was visited by Caesar's ghost in his tent the night before a battle (4.3.274). is asked why he appeared, he says "To tell you that you will see me in Philippi." which leads Brutus to fear his prophesied death in Philippi (4.3.284). The appearance of Caesar's ghost also brings back memories and feelings of Brutus' betrayal and role in Caesar's death, thus dragging him further into misery as his past sins weigh on his life.