First I should say I'm a many decades long Heinlein fan and have read almost everything he wrote 3, 4, or 5 times, except for several books that came out during the later part of his career when I was in grad school, and what with school, career, family, and so on, I didn't get around to them until about 10 years ago, and this one until now. I was saving it for a rainy day, and looked forward to it.

Unfortunately, the book qualifies as a more than a minor disappointment, and I say this as someone who truly loves Heinlein's works individually and as a whole. Since that obviously deserves some explanation, I go into several of the reservations I have about the book below.

First a brief overall description. In addition to all the discussion of n-dimensional geometry and the professor's new invention that allows universe-hopping, there is a considerable fantasy element to the book, although it takes until page 330 for that to become clear. Fans of Heinlein will know what I mean if I say that makes the book sort of a combination of his novel, Glory Road, and his short story, And He Built a Crooked House.

Although the concept is great--alternate world hopping by means of the professor's new n-dimensional space-time invention--by page 250 (which is halfway through the book) we have had a book that is mostly dialog about navigation and astrogation, and the ship's computer's capabilities in that regard, but only three brief action sequences where anything of any importance occurs, and then Heinlein returns to the interminable discussions of Gay Deceiver's (the name of their ship) computer and navigation talk. Finally, by page 271, the novel finally really takes off with a situation that Heinlein develops for the next 40 pages or so. But except for a few key facts and background information that one learns during that time almost the entire novel up till there is pretty thin gruel.

I can handle a bit of ballistics and navigational tech talk as much as anyone (I once made my living as an engineer and computer geek), but here it's just too much of a good thing. If you liked all the astrogation in Starship Troopers or Starman Jones, you might enjoy this too, but there's about five times as much of that, and about one-fifth as much action. It's as if Heinlein hoarded all the knowledge from his Naval experience calculating trajectories on incoming kamikazis, and poured all of that knowledge into this book. While that might make it interesting as a book on ballistics, as a strategy for a novel it leaves something to be desired.

There are extended discussions of leadership qualities, and at least three long arguments about who should or shouldn't be the captain, with the resident captain trying to do a job they absolutely do not want and threatening to resign, and wishing that somebody else would do it. While this is interesting in an academic sort of way, it does very little to increase the interest in the book, and just makes the reader want to slap all these recalcitrant, sensual geniuses upside the head and tell 'em to stop whining about every little thing they're unhappy about that the captain is doing and let's get along with the action and the real story already.

There are also discussions of military protocol, diplomatic protocol, written vs. verbal orders, how to resign a captaincy, ship's stowage, women's clothing, why women should never tell the man the truth, why women are superior to men, why women should still obey their husbands, Euclidean geometry, non-Euclidean geometry, basic topology, and dozens of other sometimes interesting, and sometimes not very interesting, topics.

Nevertheless, there were a couple of surprises that definitely made the book worth reading for me. I won't mention exactly what it is so as to spoil the fun, but starting at page 330 they discover an alternate world that appears to be literally based on a certain famous storybook fairy tale land which turns out not to be a fairy tale after all, and includes all the main characters familiar to all of us from the movie that was made based on the children's book. And other different fantasy and fictional stories dominate the rest of the novel.

I thought I'd mention a couple of minor scholarly points. After the crew has to make a couple of dimensional jumps to escape unfriendly locals, they jump to a universe in which the Russians and British control Mars. The Russians they encounter are paranoid and accuse them of being spies, so they have to bug out again, and they go over to the British section. Heinlein makes a point of mentioning that the British have a tradition of decent behavior and of following protocol, and so they expect better treatment there.

What's funny about this is that when they do make contact with the British, the captain at the time, Aunt Hilda (Zebediah having relinquished command in frustration earlier), treats them rudely and with suspicion. They do eventually land and are treated cordially by the British as was expected. This is funny because in Daniel Defoe's famous classic, Robinson Crusoe, the same thing happens. Crusoe spends 18 years on the island, and a passing British ship finally lands and discovers him. Despite the promise of being rescued, Crusoe isn't exactly overjoyed at meeting these strangers, and again, treats them with paranoia and suspicion, although all works out in the end.

Heinlein almost certainly knew the Defoe book quite well, and so I thought the similarity between the two encounters was interesting and perhaps is his allusion to the earlier book about another lone outcast, just as the four main charaters in Number of the Beast are now outcast from their world.

One other minor thing. At one point, where the women are getting formally dressed for their reception party by the British, one character makes an offhand comment about the origin of lipstick, but doesn't explain it. Well, it goes back to ancient Sumeria, where prostitutes wore it to advertise that fact. Actually, only certain ones did. The ones with lipstick were advertising the fact that they performed f_llatio, which apparently not all prostitutes did. This just proves again how widely read Heinlein was--not all of it was engineering and math and science. :-)

Heinlein even pokes fun at himself. At one point, during a conversation about favorite books, one of the characters mentions Stranger in a Strange Land, and someone comments, "Some writers will do anything for money." :-)

One minor piece of trivia. At least twice in the story, one of the characters says, "Who's your fat friend?" I didn't understand the context, since the phrase seems to pop up out of nowhere, but the only association I have for it is that Stewart Granger says it to Peter Ustinov in the 1954 movie, "Beau Brummell." I don't know if Heinlein is making an obscure allusion to the old movie or not, but I mention it for what it's worth.

But getting back to the book as a whole, I suppose by this time Heinlein's fame was such that no editor dared to touch his work, but this book could have been cut down by a factor of probably two and very little except all the computer and navigation talk would have been lost. I give the book three stars as an old, diehard, Heinlein fan, and if you're one you will probably want to read it, but if you're a first time reader, pass this one by and try one of his better novels, of which there are dozens.

I enjoyed everything I've read from Robert Heinlein. This book had lots of potential and I liked the concept but hated the voice of the story. It was like he was getting lazy, sounded bombastic and I hated it. I cherish books but this one went into the nasty garbage can at work, only ever threw away one other book and it was worse but it went in the garbage for the same reason, I read for stories not to hear an author try to show off how famous or witty he can be.

Heinlien ... what can be said that I could add to it. I enjoyed the book, and wish it were real and I were the lead person, ok I can dream can't I?

While I agree with most reviewers that this is not his best work, it is my personal favourite. The characters are likeable, and I love that Heinlein uses this to pay homage to some of his favourite writers, from Lewis Carroll to his contemporaries. This book introduced me to Edgar Rice Burroughs, convinced me to read the Oz books by L. Frank Baum, and sent me on a mission to discover the identities of the other authors into whose worlds Heinlein's characters jump.

True, this book is not for everyone, but I found it delightfully funny with wonderful dialogue between the four main characters. I also thoroughly enjoyed the interplay with characters from other eras and novels. If you are leary of spending the money to buy a copy, run down to your local library and check it out. It's worth the time, and you may find you really like it.

Although I myself confess I am no great fan of Heinlein's, I found it hard to believe this was written by the author of "Stranger in a Strange Land" which is a masterly work. The idea behind "The Number of the Beast" is appealing: a vast number of alternative universes, endless possibilities for exploring mysteries and opportunities for a real sense of wonder. Unfortunately this is all wasted as heinlein trawls seemingly without purpose through an interminable series of unfunny jokes and mundane inanities. For example he invents a universe just like ours except with no letter J. He indulges his predeliction for creating middle aged women referred to as "Auntie" and adopts a writing style which actually manages to parody his own already flawed and overly jaunty mannerisms. The satire is lost in a tale that is quite simply, utterly lifeless. In short , "The Number of the Beast" is a disaster and caused me to avoid Heinlein for years until I read "Stranger in a Strange Land." Even though I don't really like his works as a whole, even I was able to recognise the extent to which he has fallen below his own standard with this trash.