How has ambition affected the character of Lady Macbeth?

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, she flippantly 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.