Tim Burton’s The Nightmare Before Christmas is rich with wildly imaginative and speculative mythology that Disney has not further explored onscreen since its premiere for various reasons. It is an animated classic that is perfect as a standalone film not just for Halloween and Christmas. But thanks to the 2022 young adult novel, fans get a peek into what comes next for Jack Skellington and Sally. This suggests that there's more to the "happily ever after" ending of the movie.