Three witches plot to deceive Macbeth
Macbeth, a heroic warrior, wins another battle for his King
The three witches tell him and his partner Banquo of a prophesy that says that he will become the Thane of Cawdor and the King
Macbeth is initially skeptical, but once he is given the Cawdor title by the King, he tells his wife, Lady Macbeth
Lady Macbeth interprets this as a call to murder Duncan (the King), and manipulates Macbeth agreeing