Forres — Duncan names Malcolm heir

The royal palace at Forres. Duncan asks whether the old Thane of Cawdor has been executed. Malcolm replies that Cawdor was put to death and went well — he confessed his treasons, repented, and "very frankly... begged your highness' pardon." Duncan delivers the line that becomes the play's first major irony: "there's no art to find the mind's construction in the face. He was a gentleman on whom I built an absolute trust." He says it just as Macbeth — the new Cawdor — enters the room.

Duncan greets Macbeth and Banquo with full ceremony and great warmth. He praises Macbeth's service in extravagant terms; Banquo too is embraced. Then, with no warning, he announces a decision. His elder son Malcolm is to be named Prince of Cumberland — Scotland's official heir. The succession is now declared; the throne, until this announcement still vaguely available, is now closed. Macbeth steps aside and speaks an aside that the audience hears and Duncan does not: "the Prince of Cumberland! That is a step on which I must fall down or else o'erleap, for in my way it lies. Stars, hide your fires; let not light see my black and deep desires."

Duncan, oblivious, announces he will visit Macbeth's castle at Inverness that night to celebrate. Macbeth offers to ride ahead to make ready. He leaves. The scene closes with Duncan praising Macbeth one more time to Banquo — "he is full so valiant, and in his commendations I am fed; it is a banquet to me." The dramatic irony is heavy enough that the audience can almost feel it. The man Duncan is most lavishly praising is, in his own words, hiding his black and deep desires from the stars and riding home now to consult with his wife about murder.