Scene 1: Forres. The palace.
Banquo is worried that his old friend and fellow nobleman Macbeth did not obtain the throne honestly, and his suspicions seem confirmed by the rumours of the late King Duncan’s sons Donalbain and Malcolm telling everyone that Macbeth is a traitor who has usurped the throne. Macbeth, in turn, is troubled by the witches’ prophecy about Banquo; if it comes true, just like his own has come true, he has in fact murdered Duncan for Banquo’s heirs, not his own. Thus, Macbeth invites two murderers to his castle and talks them into killing Banquo and his son Fleance for him. Banquo needs to ride somewhere, and Macbeth tells him to be back in time for the big feast that same night, although he knows that Banquo will probably be dead by then.
Scene 2: The palace.
Before the feast, Macbeth speaks with his wife, Lady Macbeth. He is deeply troubled by what he has done and increasingly paranoid about...