In William Shakespeare's play Macbeth, the first meeting of Macbeth with the witches occurs in Act 1 Scene 3 on a heath near Forres during a thunderstorm. In this meeting, the sisters hail Macbeth as Thane of Glamis, Cawdor, and king. At first Macbeth is frightened by the witches, but nonetheless curious about their predictions. It is only after the conversation with the witches, when Angus explains that Macbeth has been made Thane of Cawdor, that Macbeth begins fully to trust the witches' predictions. With this trust comes increasing self-confidence and the disappearance of the moral scruples that initially made him wary of the witches.
The second meeting of Macbeth with the witches occurs in Act 4 Scene 1 in a cave. Macbeth, rather than meeting the witches by accident, has deliberately sought them out. He has changed greatly, from a noble and loyal soldier to an evil murderer. The witches, on hearing him approach, notice this change and say:
By the pricking of my thumbs,
Something wicked this way comes.
Rather than just listening to the witches, he makes demands of them. Rather than simply speaking their predictions, the witches call forth apparitions, who speak to Macbeth.