In medieval Scotland, Macbeth, a general in King Duncan's army, and his fellow soldier, Banquo, are returning from a successful battle. On a barren heath, three witches appear and greet Macbeth as "Thane of Glamis," "Thane of Cawdor" and "King hereafter." They also prophesy that the future heirs of the throne will be descended not from Macbeth, but from Banquo. The witches disappear, and a messenger from the King arrives announcing that Macbeth has been named Thane of Cawdor, thus fulfilling the first part of the prophecy. King Duncan declares that he is nominating his son, Malcolm, as heir, and announces that he will spend the night at the Macbeths' castle.
Alone, Lady Macbeth reads her husband's letter describing the witches' revelations. She fears that Macbeth lacks the courage to commit murder and seize the crown. Returning home, Macbeth expresses reservations about murdering the King, but Lady Macbeth convinces him that the deed must be done. That night, Macbeth stabs the sleeping Duncan, and two guards are framed for the crime.
The next morning, Macduff, a nobleman, discovers the body of the King. The King's son, Malcolm, flees to England, and the lords of the kingdom vow to avenge the King's murder. Macbeth is appointed King, but with the witches' prophecy in mind, he arranges for the murders of Banquo and his son, Fleance. Although Banquo is killed, the hired assassin does not succeed in killing Fleance.
At a royal banquet, Macbeth sees Banquo's ghost sitting in his chair, disrupting the ceremonies despite Lady Macbeth's efforts to control the situation. He returns to the witches, who share new visions with him: to beware Macduff, that he can never be killed by "one of woman born" and to never fear until he sees Birnham Wood begin to move. These twisted predictions lead Macbeth to think that he is safe from harm, although the witches still show that Banquo's descendants will ascend the throne.
When Macbeth learns that Macduff has fled the country to...