"Second Witch: All hail, Macbeth, hail to thee, Thane of Cawdor!" The quote above occurs when the three witches cross Macbeth's path, and address him as the Thane of Cawdor, something he is not. This prophecy, when it turns out to become true, becomes Macbeth and Lady Macbeth's driving ambition. To make Macbeth King, at all costs; even if it means killing their loyal, good King. This realization haunts Macbeth for the entire play.