Rachel Cusk is fast becoming the most promising young British author who just keeps making promises. She’s prolific but unperfected. Last year’s “In the Fold” was a romp, a country-house drama refitted to allow room for a contemporary mid-life crisis: In today’s world, the old plot of class cannot quite obtain. Crass Britannia prevails: The dark past of the moneyed isn’t nearly so discouraging, to the narrator, as is finding himself trying to relive a New Labour version of “Brideshead Revisited.”

“Arlington Park” (Farrar, Straus and Giroux, 256 pages, $23) is different, though slight in its own ways. Ms. Cusk situates an ensemble cast in the eponymous suburb; all are mothers. She has written another, nonfiction book, called “A Life’s Work: On Becoming a Mother” (2003), and judging by the acuity evinced here, motherhood is Ms. Cusk’s great subject.

Ms. Cusk does not romance children. “You’re ruining my life! You’re ruining my life!” declares Maisie, hurling her daughter’s lunchbox at the kitchen wall.

Within “Arlington Park,” other people’s children become an extra, equally provoking category. Amanda, the most clueless of her characters, finds another woman’s child marking up her sofa:

“How dare you?” she said in a savage whisper in his ear.

Pens were scattered all over the carpet. There were other, different coloured stains there, where their inky, suppurating tips touched the beige fibres and bled into them.

“I could kill you!” she whispered. “I could kill you!”

She threw him back down on the cushions. His body felt unfamiliar — his whole being recoiled from her in its half-formed confidence.

Even positive experiences with other people’s children can touch a nerve. The same Maisie who destroys her daughter’s lunchbox had saved a child earlier that day. Jasper, the toddler son of Stephanie, had bobbled out behind an SUV. Maisie scoops up the child, and holds him there, in protest, bawling out the guilty woman driver: “This is a child!” Later, Maisie tells her husband about the woman driver: “She was this stupid little woman with dyed blond hair and gold earrings and she sat up there about ten feet above my head.” Ms. Cusk relates this anecdote twice, if only to highlight the social resentments that underlie even the most instinctual, spontaneous moments of child-rearing.

“There was something about [Maisie] that raised again and again in Christine’s mind the uncomfortable spectre of degrees.” Degrees, more imagined than perceived, thrive in “Arlington Park”; it works as a good-old novel of class, in ways “In the Fold” didn’t.

From the first page, Ms. Cusk announces that this is a grand social novel:

The clouds came from the west: clouds like dark cathedrals, clouds like machines, clouds like black blossoms flowering in the arid starlit sky. They came over the English countryside, sunk in its muddled sleep. They came over the low, populous hills, where scatterings of light throbbed in the darkness. At midnight they reached the city, valiantly glittering in its shallow provincial basin. Unseen, they grew like a second city overhead . . .”

This recalls the beginning of Jonathan Franzen’s “The Corrections” — “The madness of an autumn prairie cold front coming through” — for good reason; the weather is the first thing everyone in a social novel has in common.

But despite the grandeur written into these first pages, “Arlington Park” backs away from its ambitions. It turns out not to be sweeping so much as episodic. Five mothers get to tell their stories, which are interrelated, but quite independent, though similar. High-stepping literary imagery such as that of the opening pages eventually becomes a crutch. Desperate Juliet, on her way home, sees two swans:

They were flying side by side, throats outstretched, beneath the descending night. Their bodies were a pale, unearthly white; together they flew in a kind of ecstasy, lifting themselves from the shadows with their slow, labouring wings.

Beautiful as this is, it comes from a file marked “Epiphanic symbolism.” Ms. Cusk’s mothers leave their domestic dramas half-baked, as they would in real dailiness, yet they spot climactic imagery with plotted regularity.

Ms. Cusk does a much better job setting up the classic suburban desperation, which epiphanies serve to conclude so often. One mother feels her second child “was the stultifying noon of her day’s life.” Alternately, a very stressful day becomes “this day of her life in which all the other days seemed to be coming together and showing themselves at last.”

Up to that point in the book, the end of the third story, I felt I was in grave danger, facing the apathy and selfishness made so insidious in these normal people’s lives. But the repetitiousness and stunted ambition of the book’s form dull any sympathies. If you like to underline excellent sentences, you will do a great deal of underlining in “Arlington Park.” But, thanks in part to Ms. Cusk’s dramatic gifts, this is a novel in which you want to see what, in the end, each character gets, and on that promise Ms. Cusk does not deliver.

blytal@nysun.com