Lady Macbeth has gone mad. Like her husband, she cannot find any rest, but she is suffering more clearly from a psychological disorder that causes her, as she sleepwalks, to recall fragments of the events of the murders of Duncan, Banquo, and Lady Macduff. These incriminating words are overheard by the Doctor and a lady-in-waiting.
The staging of this scene is made clear by the first ten lines of the scene. The gentlewoman's description of how Lady Macbeth has sleepwalked in the past acts as a stage direction for the actress playing Lady Macbeth. Her agitated reading of a letter is of course a visual reminder of her reading of the fateful letter in Act I, Scene 5. More than this, Lady Macbeth is seen to rub her hands in a washing action that recalls her line "A little water clears us of this deed" in Act II, Scene 2. If these words are not enough to arouse the Doctor's suspicions, those that follow must suggest to him not only that she is suffering but also the reason for that suffering.
Lady Macbeth's speech has become fragmented and broken by an enormous emotional pressure: the suave hostess and cool, domineering wife has been reduced to a gibbering creature whose speech (almost) signifies nothing. There are no logical connections between her memories or her sentences, and indeed, the devastation of her mind is so complete that she cannot recall events in their correct order. For example, "Out damned spot" is followed by "The Thane of Fife had a wife," referring to Lady Macduff. Later we hear the line "Banquo's buried: he cannot come out on's grave," and finally she believes she hears Macduff knocking at the gate. It is as though all the individual murders have coalesced into one seamless pageant of blood. Perhaps the most ironic line is the one which near-perfectly echoes an earlier line of Macbeth's. When Lady Macbeth cries "all the perfumes of Arabia will not sweeten this little hand," we must not forget that she was not on stage to hear her husband's "Will all great Neptune's ocean wash this blood / Clean from my hand?" (Act II, Scene 2).
Lady Macbeth's line "What's done cannot be undone" not only reverses her earlier argument to her husband "what's done is done" (Act III, Scene 2); it also recalls the words of the general confession from the Prayer Book: "We have done those things which we ought not to have done, and there is no health in us." The Doctor agrees: In his opinion, Lady Macbeth needs a "divine," — a priest — more than a doctor, reminding the audience of Macbeth's earliest doubts when he argues with himself before the murder of Duncan, "If it were done when 'tis done . . . we'd jump the life to come" (I:7,1-6).
Now, though, the promise of salvation has been all but abandoned. "Hell is murky," says Lady Macbeth, and that spiritual darkness is echoed by the fact that the scene is played entirely in the dark, with the exception of one candle, which Lady Macbeth insists on having next to her. She may be sleepless, but it is her soul's rest that really concerns her.
accompt (37) account
practice (55) medical expertise
divine (71) priest
mated (75) amazed