The Reckoning: the Good Concluded
Two of the villains in the book are made into one villain for the film, making a better film villain, and one that is less of a cipher, than the one in the book.
If Nicholas is a better hero in the film, than in the book, the film's villain is nastier, meaner, and more evil, than the one in the book. In the book, he violates the boy once, then sated, breaks the boy's neck. But . . . in the film the boy is missing for two days, before being found in rigor mortis, which means he was just killed, before being found; therefore, he was, most likely, violated, not once, but many times, over a period, if not days, then hours, before he was strangled.
The final arguments found in the film, between the hero (religious) and the villain (reason) are only found in the film and not in the book.
The arguments found in the film, have more force to them, than the same arguments found in the book.
In the book, it is left open, as to whether the parents of the other dead boys, ever learn what happened to their missing sons. While in the film, they not only learned what happened, they take their vengeance out on the villain.