Macbeth and Banquo encounter three witches who prophesy that Macbeth will become king of Scotland. When the prophecies start coming true, Macbeth begins plotting to seize the throne, eventually murdering King Duncan with Lady Macbeth's persuasion. As king, Macbeth grows increasingly paranoid and has Banquo and his son Fleance killed. Macbeth's reign is challenged by the forces of Malcolm, Duncan's son, and Macduff. In the final battle, Macduff kills Macbeth, fulfilling the last prophecy and restoring order to Scotland.