There are two ways to review Robert A. Heinlein's work since Stranger in a Strange Land, excepting … The Moon is a Harsh Mistress. With that exception, there is a pre-1961 Heinlein and then there is this "new" fellow….

The old Heinlein was a crisp, slick wordsmith of uncommon intelligence and subtlety. His gift for characterization was sharp within its narrow limits, and those limits were fortuitously placed to include the archetypical science fiction hero…. All his people talked alike. You could tell the stupid and villainous from the worthy and heroic only by their choices of subject matter. But his dialogue worked; its purpose was to propel the story, and it served quite well. (p. 55)

The Number of the Beast reflects the quintessence of the "new" Heinlein. Where the pre-1961 writer clung to the old pulp tenets—Tell your story quickly, clearly, basing the resolution on physical action...