A1. By the end of the play, the tone has devolved from fearful and foreboding to deeply pessimistic. Both Macbeth and Lady Macbeth disintegrate from the charismatic and keenly intelligent characters we see at the beginning of the play into shadows of their former selves.
A2. Shakespeare's witches are prophets who hail Macbeth, the general, early in the play, and predict his ascent to kingship. Upon killing the king and gaining the throne of Scotland, Macbeth hears them ambiguously predict his eventual downfall.
