Happily Ever After : THE FIREMAN’S FAIR, <i> By Josephine Humphreys (Viking: $19.95; 254 pp.)</i>

Rob Wyatt has given up his elegant apartment in downtown Charleston, S.C., and moved to a ramshackle beachfront bungalow. He’s traded his expensive sports car for a second-hand Toyota. He’s about to quit his partnership in a flourishing law firm to do goodness knows what. He is extricating himself, in other words, from the internal wreckage of external success.

Handily enough for Josephine Humphreys’ new novel, along comes the Charleston hurricane to objectify this wreckage. Rob has turned his life upside down to find something more authentic and joyful, and the hurricane, serviceable as movie music, blows away roof and trees and deposits a grand piano outside his front door.

“The Fireman’s Fair” tells how Rob rebuilds his life, along with his bungalow, in a new and idiosyncratic style, marked by self-discovery and a quirky independence. He gets a lot of help: from Billie, a formidable waif who blows in shortly after the storm does; from his black friend Albert, a sexton and bartender, and, more than we may want, from Humphreys.

Her novel is in considerable measure sprightly and tender. But like the bride and bridegroom’s kiss, these qualities perform with an eye out for the camera. Humphreys seems to create her characters so that they can be charming, rather than creating them so that they can be however they will be. Their adjective and adverb pre-date their noun and verb. Likable as they often are, we sense the author adjusting a bow here, shifting a light there, and generally enhancing.

It is a pity, because she can write a line that is dead wonderful. Here, at the very start, in the utterly quiet morning after the storm: “Rob Wyatt sat recuperating, keeping an eye on what was out there--his ruined island town, the blue yonder--as if recovery could be gained by the old Southern method of sitting, mulling one’s fate, watching things that don’t move much.”

Or the night before, taking refuge with his dog on top of the refrigerator while the wind howls and the water rises in his kitchen--and who knows how high it will rise? We always read about hurricanes in the past tense, and know we have survived, but it’s different while they are still going on:

“For three hours he sat in the kitchen, discovering how boredom may alternate with terror, trying to stay bored.”

Or, shifting to Rob’s elderly parents across the bay, Humphreys picks out the different resilience of old men and old women. Maude is keyed up--change and action at last!--and is busily making repairs. Jack is sunk in his chair, poring through the newspaper for bad storm news and conclusions about world decline. “Jack was at that point in life (the winding down of it) when a man can see the drama of himself, and is hoping for a denouement, an outcome that will cast light on all that’s gone before. A reward, preferably; lacking that, a penalty. . . .”

Such lines are the snap of a ringmaster’s whip, shaping circus energies into performances. For the most part, unfortunately, Humphreys’ performers are cotton candy.

We never see or believe in the striving professional life that Rob has thrown over; our only glimpse is in an interview with his partner, Hank, who is simply a painted backdrop illustrating stuffy convention. Because of this, Rob’s “rebellion” is without energy or direction. He does a few things in the course of the book, but essentially he is not so much a character as an array of attitudes, all of them admirable.

He is the confidante of Louise, a restless society housewife married to Hank. In fact, Rob has always been secretly in love with her; at her wedding, he’d fantasized abduction. He never speaks, though, and when, toward the end, she asks him to run away with her, he gently declines, since he is already hooked up with Billie.

It is the right thing to do, and he does nothing but right things. He admires waitresses and paralegals and makes a point of talking to them; he has never been a snob. He democratically dishes out fish at the fireman’s annual fry-up. He despises crassness. When Hank enters a restaurant with Louise, Rob thinks: “No sense of humor. No sense of irony. No sense of absurdity or tragedy or mortality.”

Rob has chosen “frugality and decency,” he tells Louise. When he sees black people he is shy--Albert is his only black friend--but he would like to tell them: “I’m on your side.” He “would have liked to clean the Augean stables or search for a city of gold.” This is very curious voicing for a man in his 30s, even an idealistic one. It has a member-of-the-wedding sound to it; it sounds, in fact, like the awkward, luminous adolescent heroine of Humphreys’ last novel, “Rich in Love.”

Everyone plays up to him. If the other characters have a gleam of life and originality, we tend to miss it because they are used as so many studio spots to light Rob to best advantage.

Albert is given a quirky dignity. He has no Social Security number, he lives his own life; at the end, like Rob, he will throw over his job to do his own thing, in this case, to play the saxophone and teach music. But Humphreys employs him in an embarrassingly traditional fashion: as Rob’s stern but loving black sidekick, admonisher and rescuer.

Billie’s waif qualities are a mixture of cliche and originality. She is first seen at a party shredding her cocktail napkin; her fingernails are dirty. She comes to Rob for help with a kind of divorce from her amiable but possessive husband, Carlo. It has to be “a kind of divorce” because it was only a kind of marriage. They were sitting in a park one day when a real marriage was performed several trees away; Billie thinks of herself as married by osmosis.

This has some spark to it; so does her reversal on a sexual plight normally attributable to men. She suffers the equivalent of premature ejaculation; one touch and she’s away. Among other things, this has kept her a virgin for her eventual union with Rob.

Billie’s transformation from kook to masterful problem-solver is rather a lot of a good thing. She gets Rob to help her fix up his house and garden; she straightens out his parents’ old-age neuroses and, by the end--with Louise tactfully dumped and returned to a magically less-stuffy Hank--she and Rob are well into a happy ending. He has begun to practice community law, with time for bird watching.

There’s nothing wrong with happy endings. They are just as sensible as unhappy ones. The trouble with “The Fireman’s Fair” is that Humphreys has inserted her happy ending virtually at the start; it twinkles at us all through the book.