So begins William Broyles, Jr.'s fascinating introduction, written exclusively for this book, about the process and challenges inherent in writing a screenplay that was not, by design, going to have a lot of dialogue in it, and about his collaboration with two extraordinarily gifted artists, actor Tom Hanks and director Robert Zemeckis. Broyles's introduction shows how a movie and its story evolve, shift, and shape while the creators grapple with...