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 emerging from inner growth, and for God's sake never give the reader a chance to realize there's a writer involved—the new one repudiates them, deliberately.

The new Heinlein hero is perfect to begin with. The world is best served by acknowledging his perfection and acting in accordance as quickly as possible. The plot thread is a rambling one, strung with incidents whose one common purpose is to give the world, and the reader, time and evidence required to work out details of the hero's perfection. The nature of the incidents is not organic to the story. They do not grow out of the hero's explorations of his problem. They can't—he has no problems, only transient difficulties, and this is obvious from the first paragraphs.

Therefore, the incidents can take place anywhere, anytime, and must be attractive in themselves. They are not successively unlocked rooms in an unknown structure, through which the hero must pass to find the ideal egress. They are way-stations on a circular tour of the hero's nature, and they must be furnished to engage the reader's interest as a reader, rather than as an involved rider in the searching hero's head.

That results in a kind of game, with Heinlein visibly his own hero. At times he invents new-ish settings which are actually recalls of typical Heinlein settings. At other times he directly borrows settings—E. E. Smith's Lensman universe, the Land of Oz, and the universe of Lazarus Long. In every case, the reference is to the relationship between conscious author and reader, not between hero and the reader's subconscious role-playing as a hero-surrogate. There can be no doubt on either side that at all times there is a book involved. The magic of forgetting that the reader is actually sitting in a quiet room surrounded by creature comforts—that special magic which is what reading does for most of us—cannot occur. The Number of The Beast is a book for critics; for the reader as critic, not as participant. It can be impressive. It has cut itself off, by first intention, from any attempt to be compelling. (p. 56)