You never know ahead of time what something's really going to be like.
The problem with people who are afraid of imagination, of fantasy, is that their world becomes so narrow that I don't see how they can imagine beyond what their senses can verify. We know from science that there are entire worlds that our senses can't verify.
A story is open-ended. A story invites you into it to make your own meaning.
Obviously, I love to do both contemporary and historical fiction. When a hint of a story grabs me, I try to go with it to see where it will take me whatever the setting.
I know a movie and a book are two different things and you are going do different media in different ways. No author can want a movie to be exactly like the book because then it will be a bad movie.
The basic task of education is the care and feeding of the imagination.