Act I, scene i of Macbeth opens on a blustery, open area where it is thundering and lightning, with only the witches discussing their next meeting. They intend to gather around Macbeth to inform him of their prophecies. The audience meets Macbeth as he and Banquo return from battle and are approached by the witches, from whom they learn that Macbeth shall be king and Banquo's heirs will also succeed to the throne. Banquo is suspicious of the witches' intentions and reminds Macbeth that "the instruments of darkness" (I.iii.125) may be intending to betray them. Macbeth has similar uneasy feelings but his thoughts are far more violent and evil as they "shake so my single state of man" (139). Lady Macbeth also hears of the news that Macbeth will be not only Thane of Cawdor but king and she immediately starts plotting what steps she needs to take to ensure that the prophecies are fulfilled. The act ends with Macbeth determined to carry out Duncan's murder and so take his place as king.
Act II, scene i opens with Banquo and his son Fleance. Banquo's character traits are revealed as he is unable to sleep as he has been unnerved by the witches. The unsettling events that preceded his meeting with his son are preying on his mind. Banquo is, however, honest and would like to discuss the witches' prophecies with Macbeth at a time convenient to them both but Macbeth, in contrast to Banquo, lies about having even thought any more about the witches, when the audience knows it is all that he has thought about. Unlike Macbeth, it has not occurred to Banquo to take matters into his own hands. Banquo's character is further revealed in his talk of his "allegiance," (28) as his duty to his king is something he takes very seriously.