Mark Helprin is one of those slow novelists who brings out a moving, life-altering book every decade or so, like a geological fault spawning earthquakes.

This is probably good, for two reasons. First of all, it’s really depressing for an ordinary author like me to read something as perfect as a Helprin book. It makes me feel like a junior higher who’s just discovered The Lord of the Rings and sets out to pen his own epic on his laptop, in a really neat font he downloaded off the web.

Also, it’s a fact, too often overlooked in the publishing industry, that you can’t produce a superior book like one of Helprin’s in a year. Or two. Even three.

It’s worth the wait.

My favorite Helprin novel (the same as pretty much everybody else’s) has got to be Winter’s Tale. My second favorite is probably Memoir From Antproof Case. A Soldier of the Great War is tremendous, but the tragic elements were too much for me. I haven’t read Refiner’s Fire (got to look for that).

But I think Freddy and Fredericka has supplanted MFAC as my second favorite. Briefly put, it was a delight from beginning to end.

Think of an Evelyn Waugh novel, written by P. G. Wodehouse. That’s the British part.

Think of a Tom Wolf or Mark Twain novel, also written by Wodehouse. That’s the American part.

The final segment, back in England, is merely sublime and moving.

It’s been a long time since I’ve laughed out loud, again and again, over a novel. But Freddy and Fredericka did that for me.

Here’s the (ridiculous) premise: Freddy and Fredericka are a fictionalized version of Prince Charles and Princess Diana. Names have been changed to protect the innocent, but it’s impossible not to recognize the royal family here as the one we know in our own, slightly inferior world.

Freddy seems, perhaps, a bit more solid than Prince Charles. He is strongly traditional and conservative in his opinions. Sound fellow. However, he has a problem. He is prone, sometimes because of irresistible impulses, and sometimes because of what Jeeves used to call “a concatenation of circumstances” to do ridiculous things in public that get him onto the front pages of the tabloids, such as (for instance,) trying to get back in through the gate of Buckingham Palace, stark naked, tarred and feathered, with a takeout chicken box on his head.

Fredericka, on the other hand, seems even more vapid and photogenic than her real world prototype. (At one point she asks Freddy, seriously, “What is a raw egg?”) On the other hand, she seems to be something of an airhead savant. She has bizarre flashes of brilliance, doing complex algebra problems in her head, for example.

My favorite line of her dialogue: “Lord Louey sent me a book on compassion that I have to read because he wants me to be the author.”

Because of the bad press, and because he has failed an occult family test to determine his worthiness to rule, Freddy and Fredericka are sent on a quest.

They are to parachute into New Jersey, incognito, clad only in rabbit skin bikinis, to win the United States back for the Commonwealth.

Piece of cake.

What follows is a satiric and affectionate odyssey through America, in which F & F (totally unrecognized by people who’ve been looking at their pictures all their lives) take odd jobs, ride the rails, serve as forest rangers, impersonate dentists, and Freddy becomes a speech writer for a presidential candidate (who bears no discernible resemblance to Bob Dole, despite the fact that Helprin himself was chief writer for his campaign, something I suspect even he would admit is not the highlight of his résumé). Like all good travelers, they learn not only to love the new country, but to love their own country better through it.

And the final chapters, when they go home, are deeply moving, filled with hope for the world.

One only wishes Prince Charles really were Freddy. And that Di had been Fredericka, of course.

I don’t award stars to books, but if I did I’d add a star for this one. Get it. Read it. Laugh. Be touched. Thank me later.