Macbeth is a Shakespearian tragedy about Macbeth, a nobleman and renowned warrior. After witches inform him that he will be king, he travels with his companion Banquo to King Duncan's castle. Macbeth's wife, Lady Macbeth, convinces him to kill Duncan and he obeys. After killing Banquo and others, Banquo's ghost returns to the castle, haunting Macbeth. Macbeth receives a tragic prophesy from the witches, Lady Macbeth kills herself out of guilt and King Duncan's son, Prince Malcom, invades the kingdom and kills Macbeth.
In the Birnam Wood, Malcolm discusses the fortifications Macbeth has established at the castle. They decide that they should prepare for the battle by cutting boughs from the forest to disguise their numbers as they march on the castle.