The Gentlewoman reports to the Doctor that Lady Macbeth is sleepwalking and her behavior is very strange. The Gentlewoman says that Lady Macbeth gets out of bed, puts on a nightgown, unlocks her closet, writes on a piece of paper, seals the letter and returns to bed.
Lady Macbeth says things that the Gentlewoman refuses to repeat because she fears she will be charged with treason. She urges the Doctor to hear them for himself. The doctor watches Lady Macbeth and concludes that he cannot treat her illness as she needs the assistance of God. He is very concerned about Lady Macbeth’s safety and tells the Gentlewoman to watch her closely.
Menteith, Angus, Lennox and Caithness discuss the battle plans of Malcolm. They plan to meet near Birnam Wood with the others. Macbeth has secured Dunsinane, but his forces are not loyal subjects. Each vow to fight to the death to regain control of Scotland and overthrow Macbeth.
Macbeth is secure in his castle at Dunsinane. He feels confident because the Witches told him that he cannot be harmed unless the prophecies come to pass. He believes the Witches and has no fear. Macbeth dresses for battle as the Doctor Reveals Lady Macbeth’s condition to him. He asks the Doctor to find a cure for his wife. Macbeth leaves for the battle.
Malcolm, Menteith, and Siward are near Birnam Wood. Malcolm tells them they should each cut a branch from a tree from Birnam Wood and use it as camouflage. They prepare to march on to Dunsinane.
Macbeth feels confident that he will overthrow Malcolm in battle. Macbeth hears a cry and discovers that Lady Macbeth is dead. Macbeth responds by saying that life is very short. A messenger arrives to inform Macbeth that the wood of Birnam seems to be moving toward Dunsinane. Macbeth sounds the alarm and prepares to fight.
Malcolm, Siward, and Macduff arrive at Dunsinane and enter Macbeth’s castle. Macbeth and Young Siward have a fight and Young Siward is killed. Macduff comes face to face with Macbeth. Macbeth urges Macduff to leave, as Macbeth feels he has enough of Macduff’s blood on his hands. Macbeth tells Macduff that he cannot be harmed and cannot be killed by any man born from a woman. Macduff informs Macbeth that he was not born of woman, but was “untimely ripped” from his mother’s womb. Macbeth says that what the Witches said had a double meaning and he did not realize in time the meaning of their prophecy. Macduff calls Macbeth a coward and coerces Macbeth into fighting him. The two exits and continue their sword fight.