When Malcolm, Macduff, Siward and the other nobles are planning to attack Macbeth’s castle and overthrow him, in Act V, scene 4, they are in Birnam Wood, across the fields. Malcolm orders the soldiers to break off boughs from a tree in the Wood and hold the boughs in front of them as they march toward Macbeth. He says that doing so will conceal their true numbers from those watching for Macbeth, who will not be able to report an accurate count to the king. From Macbeth’s perspective, many yards away, it does look like the Wood itself is moving when the men do this. Although the Witches tell Macbeth he cannot be killed by a man “of woman born,” Macduff reveals to Macbeth that he was delivered by what we call a Cesarean section, cut out of his mother’s body instead of being born in the more usual manner. Thus, Macduff fulfills the Witches’ prediction that a man not born of a woman is the only person who can kill Macbeth.