Scene 1. The strain put on Macbeth and Banquos relationship by the witches prophecies is shown. Macbeth lies to Banquo abot his thoughts on the prophecies as which shows that he does not trust Banquo
Banquo and Fleance leave, and suddenly, in the darkened hall, Macbeth has a vision of a dagger floating in the air before him, its handle pointing toward his hand and its tip aiming him toward Duncan.
The night around him seems thick with horror and witchcraft, but Macbeth stiffens and resolves to do his bloody work.
Lady Macbeth puts blood on the kings servants to make it look like they were the one who murdered Duncan, then Macbeth kills the servants.
Macduff and Lennox appear at the castle doors looking to see the King, Macduff enters the kings room and sees that he has been murdered, and ring the alarum bell.
Donalbain flees to ireland, and Malcolm goes to England because the murder of Duncan, these leaves Macbeth in a good position because the less people he has to worry about interfering with his throne.