The three witches set the evil and somber mood that continues throughout all of Shakespeare's tragedy Macbeth. They appear in both the first and third acts and setup the prophecy of Macbeth becoming Thane of Cawdor, and then the King; however, this can only happen if Macbeth kills King Duncan. The first scene sets up the entire mood of the play, the witches are introduced here adding a superstitious feel to the play. Then in the third scene the witches give Macbeth his motivation to kill the King, as well as his motivation to kill Banquo to prevent Banquo's descendants from getting the throne. Macbeth also is lead into the killing of the King by his wife, who wants to be Queen.
             The first scene opens in a stormy meadow where the three witches are having their meeting talking about when they will meet Macbeth. The first witch says, ""When shall we three meet again..." this stresses the witches' importance in meeting Macbeth; because they need to meet him in order to get their plan in motion. The in Act I Scene 3 they meet Macbeth and start his tragic downfall.
             In scene three the three witches are interrupted by Macbeth and Banquo. They greet Macbeth in an odd manner, "All hail, Macbeth, thou shalt be king hereafter!" (Line 63). Here they setup Macbeth by giving him a prophecy that he will be King. Macbeth ponders what they said; afterwards they tell Banquo that it will not be Macbeth's descendants who will receive the crown, but instead Banquo's. This causes problems for Macbeth because Macbeth wants his children to receive the crown. After their meeting Macbeth writes a letter to his wife telling her that the witches said that he would become the King, this causes her to begin planning the death of the King.
             The witches' purpose in the novel is to set the stage for a dark and depressing play. They appear in the first scene planning to meet with Macbeth, a...