Why would the appearance of Banquo’s ghost and Macbeth’s coronation dinner signal the climax of the play?

ANSWER: At the beginning of the play you learn that Macbeth and Banquo are friends who fought together in battle. Macbeth’s decision to have Banquo killed shows just how out of control and paranoid he has become. The fact that he sees Banquo’s ghost shows that there is no turning back for Macbeth. He will be haunted by the things he has done and will keep doing them. Recall his words to Lady Macbeth, “Things bad begun make strong themselves by ill.”