Answer:
The final act of Macbeth begins with the triumphant Malcolm and his army marching towards Macbeth's castle. Macbeth, inside the castle, is informed of their approach and becomes frantic, knowing that his downfall is inevitable. He frantically orders his wife to prepare for death, and she in turn begs him to kill her so that she will not have to face the torture of being captured. He complies, and she dies in his arms.
The next morning, as the battle rages outside, Macbeth faces off against Macduff. He is confident at first, but as Macduff begins to gain the upper hand, Macbeth realizes that he is doomed. He begs for mercy, but Macduff refuses to show any, and he decapitates Macbeth. With Macbeth's death, Malcolm is crowned the new King of Scotland.