BOOK REVIEW / SHORT STORIES : Intricate Tales of Unpredictable Women, Young and Old : THE BLUE WOMAN And Other Stories <i> by Mary Flanagan</i> , W.W. Norton, $21, 320 pages

“Bad Girls” was the title of Mary Flanagan’s first collection of short fiction. Feminine “misbehavior”--along with speed, humor, unpredictability and a little magic--remains a prominent feature of the 16 new stories in “The Blue Woman.”

Flanagan, an American who lives in London, writes about women young and old, well-off and poor, mad and sane, sinned against as much as sinning. Even the victims among them have their moments of self-assertion; even the transgressors have their reasons.

In “When I’m Bad,” the teen-age narrator scrawls obscenities on the walls of her room and then stops eating because, she claims, “I don’t even deserve food.” Is she crazy? No, it turns out--only trying to justify her father’s vicious abuse, and thereby make sense of it in the only way she can.

In “The Wedding Dress,” one of two linked stories apparently based on the history of Flanagan’s own Irish Protestant family in Upstate New York, a young woman marrying a Catholic during the 1930s is told that, as a convert, she can’t wear white to her wedding. The groom is a good man and the marriage will be happy. Still, the bride needs to rebel.

Disdaining the modest beige suit that society deems appropriate, she marches down the aisle in a low-cut, fur-trimmed, slit-skirted outfit of deepest purple. “She is a stunner, a million bucks, the classiest dame in the tri-city area. She should be going . . . to lunch on the arm of a congressman . . . (anywhere but to) her own wedding.

“When she stands beside (the groom) in this dress of hers, she will look in his eyes and still see goodness. But she will see something else too, and that will be knowledge, a knowledge of her that has been hidden from him until today. And the knowledge will hurt him a little. And she will sense that and feel satisfied.”

In “Beyond Barking,” a hilarious tale set in an English nursing home, a pink-haired ex-nightclub singer called the Duchess subsists on memories and contraband gin until a chance at a last fling--with a senile old gaffer whose sex drive is still in working order--leads unexpectedly to a financial windfall.

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In “The Immortal Girlfriend,” a character we all knew in high school--a “small-town Venus”--lives fast and dies young. This is a revealing story, because geographically and in subject matter, Flanagan enters Joyce Carol Oates territory here, yet her way of exploring it is so different. Oates would focus on the individual tragedy, but Flanagan, an essentially comic writer even when her stories are sad, dwells on the myth of Estelle Vachon--in fact, her divinity:

“Some say she blew her life on giggles and romance, but I don’t think so,” recalls the narrator, a classmate. “She just needed, more than the rest of us, to express love. . . . I thought such expressions” of rapture as Estelle’s on the dance floor or in the back seats of parked cars “existed only in the movies or in the raised faces of saints.”

Flanagan tells of a stylish ascetic in the Greek islands who is imprisoned by her own perfectionism; a repressed homemaker who finally breaks out--into craziness instead of freedom; a college student nicknamed “Calypso” who draws on the power of the mythic identity laid upon her as a joke.

Magic is never far away in “The Blue Woman.” A pair of comfortable shoes knocks an entire life off stride. A rejuvenating potion (delivered in a bloody package by an idiot butcher’s boy) works only too well. The richly sensuous experience of a good restaurant lures a street waif into danger. A plumber called to fix a leaky pipe proves to be an epic hero.

Flanagan has also written two novels (“Trust” and “Rose Reason”), but here she shows all the natural short-story writer’s gifts of compression. Her endings may sometimes be too quick and glib or, alternatively, a trailing off, but nobody can begin a story any sharper or faster.

At her best, a Flanagan story is a mini-novel, covering long stretches of time and a cast of dozens, as lean as a synopsis yet packed with detail. Making a real novel out of it would seem to be gratuitous padding.

For when we ask ourselves whether we need to know anything more about these people and events than Flanagan has already told us, the answer is no.