The second meeting that Macbeth has with the witches occurs in Act IV scene 1, which comes after Macbeth has been haunted by the ghost of Banquo during the banquet scene and decides that he needs to receive more answers from the witches regarding the confusing and nebulous prophecies that they gave both him and Banquo. Thus it is that Macbeth enters the scene in this section of the play, determined to receive answers to his questions, saying to the witches the following lines:
I conjure you, by that which you profess,
Howe'er you come to know it, answer me:
Though you untie the winds, and let them fight
Against the Churches; though the yesty waves
Confound and swallow navigation up;
Though bladed corn be lodg'd, and trees blown down;
Though castles topple on their warders' heads;
Though palaces, and pyramids, do slope
Their heads to their foundations; though the treasure
Of Nature's germens tumble all together,
Even till destruction sicken, answer me
To what I ask you.
Note how desperate Macbeth is to receive his answers. He is even willing to receive them if it means that nature itself will perish and be destroyed. These lines of Macbeth present him as a man who is obsessed and haunted by what has been said to him and the many different possible futures that the prophecies could indicate. He wants answers, and he will have them at whatever the cost, both to himself and to the world at large.