Personally, I wouldn't focus on the hook until you've written the rest of the essay. In fact, in my opinion, the "hook" is one of the least important parts of the entire essay. If you are looking for a good place to start - I suggest writing your essay in this order:
- brainstorm a list of ideas that answer the prompt (tons and tons and tons - be as specific as possible)
- organze your ideas into 3 categories - these will become your 3 body paragraphs
- write thesis statement: this should basically answer the prompt and include something about your 3 categories
- outline your essay
- draft the body paragraphs first
- write the intro and conclusion
Once you've got the entire essay basically down, the "hook" should come pretty naturally - as you will know what you are hooking your audience to read.
As a matter of personal preference, I also seriously advise you to avoid the use of a question as a hook. Highly over done and terribly cheesy! :) I'm more of a "be as direct-and-to-the-point-as-possible" writer. My thought is your first sentence is going to start something like this: "In Shakespeare's Macbeth, the author..."
Now that you have some excellent ideas for your essay, maybe a suggestion for the hook can be given as it is what motivates the reader to peruse your essay:
Start with a citation of the witches' equivocation of "fair is foul, foul is fair," remarking on how this paradox directs the play. For, this paradoxical phrase is the underpinning of all the action of the play as dissembling exists in not only the witches and their predictions, Lady Macbeth and Macbeth, but also in Malcolm,who tests the loyalty of Macduff before declaring himself the one who will lead Scotland. (See the excellent suggestions in the second post.) Certainly, on the part of Macbeth and his wife, things are not always what they seem, either as Macbeth is seduced by the preternatural world and his "vaulting ambition," and Lady Macbeth is proved false by her conscience.
The appearance-reality dichotomy is at the heart of Shakespearean theatre, not just the tragedies, but the comedies too. In a tragedy like Macbeth, it is this dichotomy that builds up the tragic destiny of the protagonists. It also makes prominent the operative function of the tragic irony, especially that of words.
There is an appearance-reality conflict in the equivocation of the witches who say only to seduce and cheat.
Lady Macbeth's chastising of Macbeth is all about teaching him the art of this dichotomy, how to be an innocent flower apparently and be a serpent under it.
When Lady Macbeth is greeting Duncan at Inverness or when the porter in his drunkenness mistakes Macbeth's palace for hell, when Macbeth laments Duncan's death in a great rhetorical flourish or earlier still when Duncan talks about the impossibility of reading the mind's construction from the surface of the face regarding the Thane of Cowdor's betrayal and the ironic way it applies to Macbeth as well----all these are relevant instances.