How the ‘Train Dreams’ Writers Adapted an ‘Unadaptable’ Book: Goodbye, Elvis!

The screenwriting rule of thumb is that one page of a script is equivalent to one minute of a movie. For “Train Dreams,” the Best Picture nominee starring Joel Edgerton, it almost worked out that one page of the Denis Johnson novella equaled one page of the script and one minute of the film: The novella is 113 pages of text, the screenplay is 98 pages and the movie is 102 minutes. So the adaptation must have been easy, right?

Wrong. “Train Dreams” is a moody, evanescent book that slides...