Scene 1
Until Act 5, Macbeth has been tormented with visions and nightmares while Lady Macbeth has derided him for his weakness. Now the audience witnesses the way in which the murders have also preyed on Lady Macbeth. In her sleepwalking, Lady Macbeth plays out the theme of washing and cleansing that runs throughout the play. After killing Duncan in act 2, she ignorantly tells Macbeth that "a little water clears us of this deed" (II ii 65). But the deed now returns to haunt Lady Macbeth in her sleep. Lady Macbeth's stained hands are reminiscent of the biblical mark of Cain—the mark that God placed on Cain for murdering his brother Abel (Genesis 4:15). But Cain's mark is a sign from God that protects Cain from the revenge of others. Lady Macbeth's mark does not protect her from death, as she dies only a few scenes later.
The doctor's behavior in Act 5 Scene 3 resembles that of a psychiatrist. The doctor observes Lady Macbeth's dreams and uses her words to infer the cause of her stress. Lady Macbeth's language in this scene betrays her troubled mind in many ways. Her speech in previous acts has been eloquent and smooth. In Act 1 Scene 4, for example, she declares to Duncan:
All our service,
In every point twice done and then done double,
Were poor and single business to contend
Against those honors deep and broad wherewith
Your Majesty loads our house. For those of old,
And the late dignities heaped upon them,
We rest your hermits. (1.6.14-19)
In this speech, Lady Macbeth makes use of metaphor (Duncan's honor is "deep and broad"), metonymy (he honors "our house," meaning the Macbeths themselves), and hyperbole ("in every point twice done and then done double"). Her syntax is complex but the rhythm of her speech remains smooth and flowing, in the iambic pentameter used by noble characters in Shakespearean plays. There is a significant difference in the way she talks in her sleep in Act 5:
Out, damned spot, out, I say! One. Two. Why