The tragedy starts with the return from the battlefield of Macbeth and his friend Banquo, where they won against the Norwegians. They are going back home when three witches appear and make thrre prophecies: the first two say that Macbeth will become Thane of Cawdor and then King, the third one that Banquo's will have a royal offspring.
The first prophecy comes true when King Duncan makes him Thane of Cawdor. Macbeth comes to know that the King will go to his castle in Inverness, and he plan the King's murder with his wife, Lady Macbeth. The second prophecy comes true when they kill him and his sons run away from Scotland fearing for their lives; Macbeth self crowns King of Scotland. Shortly after, Macbeth, overwhelmed by guilt, begins to be afraid of being find out and he makes kill Banquo. After this murder Macbeth begins to have visions of ghosts of the people he has killed.
Meanwhile Duncan's sons, helped by McDuff, form an army to take revenge on Macbeth and to take the control of Scotland. Macbeth, alone, goes again by the witches who tell him to beware of McDuff; that he will be killed by a man not born from a woman, and that he will never be defeated until the Birnam Forest advances toward Dunsinane, his castle.
The man who was not born from a mother was MacDuff.
The moving wood was McDuff's army whose men had taken branches from the trees to disguise themselves.
Lady Macbeth went mad and committed suicide. The play ends with the murder of Mabeth by Mc Duff and the coronation of Duncan's son.