Macbeth ends when Macduff presents Macbeth's severed head to Malcolm, who celebrates by inviting everyone to his coronation party. Fun!
Well, what did you expect from a play about regicide? The thing is, though, Shakespeare's tragedies are also always interested in reestablishing a sense of political order and continuity. So, while Macbeth has been running amok throughout the entire play (killing kings, ordering the murders of children, hanging out with witches, and putting his own selfish needs before the good of the kingdom), we're left with a sense that Malcolm's rule will be a time of healing and restoration…or will it?
After Macbeth's severed head is delivered to the soon-to-be-king, everyone in the vicinity yells out "Hail, King of Scotland" (5.8.70). Now, where have we heard that before?
Oh, we know: that's what the witches call out to Macbeth at the play's beginning, just before all hell breaks loose. In fact, the witches say "hail" to Macbeth no less than ten times, which makes that word a loud and creepy echo by the time they're done with it. We can't help but wonder if Malcolm, who is enthusiastically "hailed" as King of Scotland, will be a good ruler or, if he'll turn out to be just as oppressive as Macbeth.
Boom. You just got Dick Wolfed.