“Sir, not I.”

– William Shakespeare

Macbeth, Act 3, Scene 6. The Lord reveals that this was Macduff’s response when when Macbeth sent a messenger to him in England to command him to return. With Banquo now out of the picture, murdered on the orders of Macbeth, Shakespeare provides another enemy and challenger to Macbeth’s position of power in the person of Macduff.