Here is a Cultural Literacy worksheet on the concept of free will. This is a half-page worksheet with a two-sentence reading and three comprehension questions.
In other words, it barely introduces, and in no way does justice to, one of the big, big questions in philosophy and religion. But as an adjunct to a fictional allegory on protagonists with circumscribed lives? This might be a useful document. In any case, it is formatted (like most of the things you’ll find on this blog) in Microsoft Word, so it is open source and therefore yours to do with as you need or wish.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.