I was not really surprised that Macbeth and Lady Macbeth both met their doom. There was plenty of foreshadowing to indicate that they would. Foreshadowing is hints to the future. For example, the witches repeatedly mess with him, especially Hecate. They are the ones that put the prophecy of him being king into his head—and his wife’s. Macbeth demonstrates indecision and cowardice early on, and only kills Duncan once he is spurred on by his wife’s relentless nagging. In the beginning it is Lady Macbeth who is power-hungry and bloodthirsty.
When Macbeth sees Banquo’s ghost, it foreshadows the downfall of both Macbeth and Lady Macbeth. They are coming unhinged. The bloody dagger Macbeth hallucinated before killing Duncan may not have been what he thought it was, and may foreshadow his own fate. This is one of the reasons why Banquo’s ghost frightens him so much. Lady Macbeth’s attempts to keep up appearances are futile. It’s also clear that first Banquo and then Lennox seem to be aware of what is going on, so Macbeth can’t get away with it forever.
Lady Macbeth’s futile attempts to wash her hands in Act V foreshadow her death, and they in turn are foreshadowed by her dismissing the blood on her hands when Macbeth kills Duncan as easy to wash away.
When Macbeth speaks to the witches in Act IV, Scene 1, it seems clear that he is in for it. They tell him that he will be doomed with the forest comes to the castle, and that he cannot be killed by a man born of a woman. He assumes he is ok, but he does ask them for clarification—which they refuse to give. In the end, when he sees the forest approaching, he pretty much decides that he is doomed and accepts his fate, but vows to go down fighting.