This is a great big adventure that's supposed to span time and space like a sprawling Universal octopus, but most of it happens on the Moon. The rest happens all over, as one would guess, but even then, rather than a big sprawling adventure (I have read big sprawling adventures and this is not one of them), it's more of an excuse for Heinlein to trot out a bunch of characters from several other books and intermingle them in a kind of giveaway fashion. I sometimes like to read science fiction and I sometimes like to read fantasy, but I don't like to read one disguised as the other.