Answer:
Act 3, scene 5 of William Shakespeare’s Macbeth adds an entirely new layer to the plot of the play. For all the scenes previous, it appears as if Macbeth is being controlled by the words of the three witches, “the weird sisters,” and the manipulation of his wife, Lady Macbeth. This scene introduces a new character that deepens the characters of the witches, explains their control over Macbeth, and shifts the power into new hands.
In this scene the reader meets Hecate. From the Greek “hekatos,” Hecate means “worker from afar,” and she is a Grecian goddess. She is mostly known for being the goddess of magic and witchcraft, though she is also associated with the night, the moon, ghosts, and necromancy. Before her appearance, Hecate is mentioned twice, both times by Macbeth. In act 2, scene 1, he says “witchcraft celebrates pale Hecate's offerings,” and in act 3, scene 2, he references a bat flying “to black Hecate's summons.” The first refers clearly to Hecate’s dominating power and control over magic, the second to her command over living beings. These quotes could be considered foreshadowing of Hecate’s dominion over the three witches and therefore Macbeth.
In act 3, scene 5, only one witch speaks, and briefly while the rest of the scene is taken up by a monologue of Hecate’s. In only a few lines, Hecate scolds the witches for dealing with Macbeth without including her, furious that she, their master, was not permitted to play with him herself. She then shames them for their lack of control over Macbeth, calling him a “wayward son” who acts for his own purpose and not that of the witches, implying a weakness to their art. After this brief but stinging reprimand, Hecate offers the witches amends if they will now do as she says in dealing with Macbeth. She lays out the plans for act 4, scene 1, when the witches reveal the three apparitions to Macbeth. Hecate informs them she will prepare that night three “artificial sprites” and “by the strength of their illusion” confuse Macbeth even further. This shows the true power of Hecate. She will not merely perform magic, but create an entirely new fate for Macbeth completely on her own. It could be considered that Hecate now chooses to destroy Macbeth simply for the sake of showing off and having a little fun.
Perhaps, though, the greatest proof of Hecate’s power and wrath is the reaction of the three witches. Up till now, they have seemed to be the most powerful beings in the play, but now they are ashamed and scorned. They immediately race off to do Hecate’s bidding, most likely fearing her punishment should they not obey. The three witches are simply tools to Hecate, their previous dealings with Macbeth trivial and easy, but Hecate is now preparing to bring the true greatness of witchcraft upon Macbeth. This scene is proof that Macbeth no longer has any control over himself or his life.