In "Macbeth", how does Lady Macbeth disintegrate?
This is actually just a one-scene question: the answer to it appears, really, in just a single scene of the play. Which is funny, because you might expect Shakespeare to take a little more time to have a character crack up and fall apart than one scene: indeed, for many years, people came up with theories that there was a missing scene for Lady M (most notably, the famous actress Dame Edith Evans).
You see her in Act 3, Scene 4, desperately chastising her husband and trying to hold the banquet together:
You have displaced the mirth, broke the good meeting,
With most admired disorder.
There is - I think - a metaphor in the way that the banquet (civilised, homely, ordered) descends into rambling chaos, ending with the guests all fleeing from the castle. Lady M's mind, in the next scene we see her, has also descended into chaos:
Out, damned spot! Out, I say! One–two— why then ’tis time to do't. Hell is murky. Fie, my lord, fie! A soldier, and afeard? What need we fear who knows it, when none can call our power to account? Yet who would have thought the old man to have had so much blood in him?
The lines jump back and forward in time: "out damned spot" is the blood long after the murder, "one-two..." is the bell chiming before the murder, and her address to Macbeth ("Fie, my lord, fie...") is clearly part of a conversation just minutes after the murder. How does Lady M disintegrate? She goes mad.