Banquo and his son, Fleance, are at Macbeth's inner court at Glamis. They're both feeling a little twitchy.
Macbeth then enters with a servant, and Banquo notes that the new Thane of Cawdor (Macbeth) should be resting peacefully considering the good news he got today.
They reminisce about those wacky witches they met the other day, and then everyone leaves Macbeth alone on stage.
Just in time, too, because things are about to get real: Macbeth has a vision of a dagger that points him toward the room where Duncan sleeps. The dagger turns bloody and Macbeth says the bloody image is a natural result of his bloody thoughts.
A bell rings, which is Lady Macbeth's signal that it's time to rock and roll.