Macbeth, Thane of Glamis, receives a prediction from three witches that he will soon be Thane of Cawdor and later King of Scotland. When the former comes to pass his ambitions are stoked. Spurred on by the even more ambitious Lady Macbeth, he murders King Duncan and assumes the throne. This will not be the end of his killing but forces are being assembled to thwart his ambition and stop his rampage.
—grantss