Three witches anticipate a meeting with Macbeth.
King Duncan hears a report of how his generals Macbeth and Banquo defeated the Norwegians and the Scottish rebels. The witches gather on a heath, and meet the generals returning from the war. They predict Macbeth will become Thane of Cawdor, and one day king, and that Banquo will be the father of kings.
Macbeth is then greatly impressed when he is greeted by Ross and Angus with the title of Cawdor. Duncan greets Macbeth with great praise, and proposes to visit him. Macbeth writes to his wife telling her of what has happened and the King's plans. Lady Macbeth, seeing the opportunity, plots with her husband how they might kill Duncan when he arrives.
After initial enthusiasm, Macbeth changes his mind, but Lady Macbeth persuades him to carry out the deed. He murders Duncan, making it seem that the servants were to blame, and describes the scene to his wife. She finds herself having to return the daggers he has used to Duncan's bedroom, and her hands become covered with blood too.
They retire when they hear repeated knocking at the castle gates. Macduff arrives, and has a brief exchange with the Porter. He discovers the dead king, and rouses the castle. Malcolm and Donalbain, concerned about their own safety, flee abroad. Soon after, Ross and Macduff reflect on what has happened, and Macduff reports that Macbeth has been made king.
Macbeth is concerned about his position, very aware of the prophecies about Banquo. He arranges with a group of murderers to kill Banquo and his son Fleance; they succeed with Banquo, but Fleance escapes. At a dinner that night, where Banquo would have been the chief guest, Macbeth is terrified by the appearance of his ghost. Macbeth decides to return to the witches to find out his fate.
They tell him that he should fear Macduff, that no man born of woman can hurt Macbeth, and that he will never be vanquished until Birnam Wood comes to Dunsinane. They then show a line of eight kings deriving from Banquo. Macbeth learns that Macduff is fled to England, so he arranges the death of Macduff's wife and children. Macduff meets Malcolm, who tests Macduff's allegiance to Scotland by first painting a bleak picture of his own personality as a future king, then revealing his true character. They agree to fight together, with English support. During the meeting, Ross brings news of the murder of Macduff's family.
In Scotland, a doctor and gentlewoman observe Lady Macbeth sleepwalking, imagining she cannot clean her hands of Duncan's blood. The Scottish nobles gather, and Malcolm orders his men to camouflage themselves with tree branches as they attack, thus giving the appearance of Birnam Wood approaching Dunsinane.
Macbeth learns his wife has died. Fearing no man born of woman, Macbeth fights on, killing Young Seyward, but on meeting Macduff he learns of Macduff's caesarian birth.
Macbeth refuses to yield, is killed by Macduff, and Malcolm is proclaimed king.