In Shakespeare's Macbeth, Act V, Scene I, the theme of guilt and the motif of blood is furthered by the delusional Lady Macbeth's famous lines,
Out, damned spot! Out, I say! One: two: why, then 'tis time to do 't. Hell is murky. ...What need we fear who know it, when none can call our pow'r to accompt? yet who would have thought the old man to have had so much blood in him? (5.1.31-35)
Her guilt and mounting madness are clearly evident in this passage as Lady Macbeth becomes obsessed with her imagined blood-stained upon her hand; "Hell is murky" suggests that Lady Macbeth has already seen hell. Even the gentlewoman remarks, "She has spoke what she should not" (5.1.41). Also, it may be a reflection of her increasing insanity as she does not speak in verse as it is most unusual for a major character in a Shakespearean play to speak in something other than iambic pentatmeter. The doctor echoes this sense of impending doom expressed by Lady Macbeth as he says,
Foul whisp'rings are abroad. Unnatural deeds
Do breed unnnatural troubles. (5.1.65-66)
This theme of guilt is also felt by Macbeth himself later in Scene 3 as he, too, has a sense of fatality when he says,
...I am sick at heart...
....My way of life
Is fall'n into the sear, the yellow leaf,...
As honor, love, obedience, troops of friends,
I must not look to have; but in their stead,
Curses not lou loud by deep...(5.3.222-29)
In Act 4, Macbeth has reached the height of his rise to evil with his killing of Lady MacDuff and her young son. He has gone far beyond killing to fulfill his ambition. He is now in a mad frenzy and kills for seemingly no purpose, just to inflict harm. In Acts 1-4, there have been fewer scenes in each act (6 or 7 scenes at the most), and they have been long scenes because their purpose is to build up the story.
Beginning in Act 5, however, the scenes are many but they are short (11 scenes in Act 5). This is because Act 5 begins the unraveling of Macbeth and Lady Macbeth and dramatically, this occurs rather rapidly. In this first scene, a doctor and servant are observing Lady Macbeth who is sleepwalking because of her guilt. Lady Macbeth has succumbed to her guilt and is nervous, paranoid and finally mad. She believes her hands are stained with Duncan’s blood. Whereas earlier in the play she told her husband, after the murder, that a little water would cleanse them of the deed, now she cannot wash out the “damned spot” no matter what she does. This is because it is she that is damned. As this last act unfolds, both Macbeth and Lady Macbeth experience a total reversal and ultimate demise.