Act 5, Scene 3: In his castle, Macbeth is overconfident in his victory. He knows that he cannot be defeated until "Birnam Wood remove to Dunsinane" (Act 5, Scene 3, Line 2) and a man "not of woman born" kills him. Thus, he does not fear the fast-approaching Malcolm and his men. A servant tells Macbeth that there are ten thousand English soldiers directly outside of the castle. Macbeth dismisses the servant's fear and rashly decides to ride outside and fight. The doctor enters and tells him that Lady Macbeth is very ill. He says that he is unable to treat her because her ailment is purely mental, not physical.
Act 5, Scene 4: Malcolm, Siward, Macduff and the English forces have met up with Menteith, Angus, Caithness and the Scottish soldiers. Malcolm orders each man to chop down a tree in Birnam Wood and carry it until they reach Macbeth's castle. He says that this will hide their true numbers until they are ready to attack. Thus, Birnam Wood is traveling towards Dunsinane-part of the witches' prophecy has come true and Macbeth is doomed. Siward reports to the group that Macbeth remains confident in his castle at Dunsinane. The now combined Scottish-English army continues to march towards Macbeth's domain.