Answer: Macbeth declares that he will fight, but remains reassured by the prophecy that he cannot be defeated by anyone born of a woman. Young Siward challenges Macbeth and Macbeth kills him. Macduff enters the castle, seeking vengeance on Macbeth for the murder of his family. Malcolm and Siward enter the castle. Macbeth kills young Siward in battle and finds out that Macduff was not born of a woman. A Scottish army is heading towards Birnam Wood to join Malcolm and his English army. Malcolm arrives with the Scottish and English troops at Dunsinane. Macduff kills Macbeth and cuts off his head.