How does King Duncan's death affect Macbeth & Lady Macbeth?

Obviously, you already have some strong ideas about how the murder affected both of them. Macbeth has started to go mad, you say, but his wife is still calm, cool, and collected, except for her fear that he might somehow give them away. You're ready to start writing. All you need to do is pinpoint some quotations or incidents from the play that support your ideas. What does Macbeth say or do to convince you that he's losing his sanity? What does lady Macbeth do or say to convince you that the killing hasn't rattled her? What does she do or say to convince you that she's worried about her husband "blowing their cover"?