A Story Told by Two Liars : THE SWEETHEART SEASON.<i> By Karen Joy Fowler (Henry Holt: $23, 352 pp.)</i>

Except in the speeches of conservative politicians and a lingering twinge among some of us born before World War II, little but tatters remains of the bucolic image of the United States at mid-century: a squeaky clean car and house, the wife in fresh lipstick and blouse serving a homemade dinner to the husband and their two children, neighborly neighborhoods, long summer evenings, dependable jobs, patriotic celebrations and faith in our leaders, our present and our future.

The “our” was both shallow and narrow. It omitted blacks, slum dwellers, dissidents--McCarthyism was slouching to be born--much of the rest of the world, a tragic sense of life and imaginative space for the generations to follow.

No end of writers have pointed all this out over a range of anger, parody and several kinds of understanding from chilly to warm or, in the luminous case of a John Updike, dispassionate passion. Karen Joy Fowler’s “The Sweetheart Season” hops all around the range. It is a combination of inquiry, skepticism and sympathy voiced with a zany appeal, a hint of magic and some unsteadiness.

As in her first novel, “Sarah Canary,” a chronicle of the Far West in the mid-1800s, the magic in “Sweetheart Season” is a kind of time travel. The reader is neither firmly there nor firmly here but floats in between, disconcertingly free of gravity.

The story of Irini Doyle’s 19th year--1947--in the little town of Magrit, somewhere at the northern end of the Midwest, is told at two removes. The narrator is her daughter, now in her 40s, who recounts and embroiders what Irini had told her. Both, we are advised, are unreliable. Irini, true to her time, put a positive spin on everything. Her dying words to her daughter were: “I’m just fine. You go and have a nice dinner.” True to her own time--the ‘60s and ‘70s--the daughter is a negative spinner. “You would do well therefore,” she tells us, “to keep in mind that this is a story told by two liars.”

We are also to keep in mind that 1947 came at a time of unparalleled national confidence. It followed the victorious end of a war, the narrator reminds us, “waged in an almost total absence of doubt. To us today, of course, this might as well be fairyland. The people who raised us are no more like us than the fairies are. Irini was 19 years old, and even though she had lived through a whole war, nothing yet had hurt her enough to leave a mark. This makes her even harder to imagine.”

Thus “The Sweetheart Season” has the double feel of a fairy tale told by a skeptic--one who is skeptical of her own skepticism. Its flavor is tart, comic and unreliable; a balloon that defies gravity at one moment and, at the next, loses confidence and deflates.

Magrit lives by breakfast cereal: the great Margaret Mill company founded and still run by Henry Collins, a 92-year-old inventor-eccentric who emerged from New England and created a paternalistic empire. The reader will think of Kellogg’s and also of General Mills, particularly since the company’s icon is Maggie Collins, named after Henry’s adored mother. Betty Crocker-like, she dispenses recipes and household hints.

The fact that she is imaginary has not prevented her from being voted the most-admired woman in America. Furthermore, any company employee heard doubting her reality is required to deposit a quarter in a blue jar. Since Henry is virtually deaf the jar contains less than a dollar.

Maggie’s newspaper advice reflects the theology of 1940s America: She counsels those who write her about etiquette (how many times should you apologize if you spill food on the hostess’ tablecloth?), the problem of uncolored margarine and what women should do to be marriageable. “Every girl must learn early not to compete in sporting events with men. It is not the possibility that she might lose that must be avoided. It is the very real possibility that she might win.”

This trips up Irini, who works in the company’s scientific kitchen and tries, not entirely successfully, to fit in. Her father, a free-thinking original who escapes censure because he is an alcoholic--something Magrit can understand--summons her from time to time to his favorite bar to display her talent for arm-wrestling. To her embarrassment, she keeps winning.

Even more embarrassing, her father feels obliged to explain the facts of life, since her mother is dead. He does it while playing catch, throwing the ball high in the air so she has to stand close to get it. She indignantly refuses to believe that her neighbors actually get undressed and go to bed with each other. Later, lying in bed herself, she fantasizes kissing a man but sits up quickly when she imagines him touching her breast. “What kind of girl did he think she was?”

“The Sweetheart Season” rambles dizzily among the apparent placidities and comic oddities of Magrit (at times we think of Garrison Keillor’s Lake Wobegon) and the darker hues that nudge the affable surface. At the start of the century, for instance, to provide power to the mill, Collins dammed the river above the town, thus drowning what was then Upper Magrit. Residents were paid “generously”--a few cents on the dollar--to move; 50 years later, though, there remains a chilly silence between the descendants of the Upper Towners and of the Lower Towners among whom they settled.

By 1947, the general amiability shows other signs of threat. (It is nicely unclear whether this is Irini’s recollection or the daughter’s retrospective addition: The uncertainty removes any danger of the didactic.)

In any event there are problems. Henry Collins grows too feeble to make his annual ritual swim across the dam pond. Somebody is sabotaging the Maggie column. One recipe recommends cayenne pepper for a dessert; another arranges a banana protruding out of a pineapple ring and, to make matters worse, calls it “Jack Be Nimble.” Things go downhill from there.

Magrit suffers an acute postwar man shortage--not because the men were killed in battle but because they refused to return to such a boring place. There are talks of unionizing and restlessness among Irini’s friends and fellow workers.

Henry’s solution is to organize an all-woman baseball team. It will travel to neighboring towns, play the men and boys, drain off energy and perhaps scare up some matrimonial prospects. Fowler writes at length and amusingly about the traveling team’s ups and downs--at one point their bus capsizes--but there is a certain lack of conviction, an anticlimactic quality. It organizes a plot and plots are not the author’s best talent.

What gives “The Sweetheart Season” its distinction is the delicate comedy with which Fowler creates her townspeople; particularly Irini, her father and half a dozen others, including Henry Collins’ wife, an all-American communist and his counterpart in eccentricity. They make an alluring crew for her time-travel venture into the mysterious universe that lies half a century behind us.