By Alice Elliott Dark

Simon & Schuster. 288 pp. $23

"It was a straightforward, simple life. She'd tried never to ask for too much, and always to be of use. Simplicity had been her hedge against bad luck," writes Alice Elliott Dark in the title story of "In the Gloaming." "It had worked for so long." Those subtle moments--when things don't work the way they used to, when nothing has changed and yet everything is different--occur again and again in this marvelous collection of short stories.

In "Home," a woman in the early stage of Alzheimer's disease moves from the home in which she's lived for 60 years to an assisted-living facility--a sly musing on the very nature of the word "home." Ian, the young married man in "Close," is weighing whether to stay with his wife or to start over with his mistress, Tasha, and his struggle to do the right thing is both sad and funny. ("He was definitely ready to lead a clean life again. But with whom?")

The title story is the most familiar; indeed, it's one of the better-known short stories of the past decade. John Updike selected it for his "Best American Short Stories of the Century," and Christopher Reeve directed a television adaptation with Glenn Close. Dark's original story is far sparer, a quiet tale of a mother taking care of her son Laird, "the love of her life," in his last days of AIDS-related illness. Dark sketches their sometimes bumbling attempts to connect with spare understatement, including the moment when Laird dies:

"All she knew was that at a certain point the fire was in danger of dying out entirely, and when she got up to stir the embers she glanced at him in spite of herself and saw that his fingers were making knitting motions over his chest, the way people did as they were dying. She knew that if she went to get the nurse, Laird would be gone by the time she returned, so she went and stood behind him, leaning over to press her face against his, sliding her hands down his busy arms, helping him along with his fretful stitches until he finished this last piece of work."

Most of the other stories here are equally effective, and affecting. Much of Dark's territory--an East Coast WASP enclave called Wynnemoor--may be John Cheeverville, but Dark's soft-pedaled juxtaposition of comfortable existences with nasty surprises recalls Rachel Ingalls, or a mild-mannered Roald Dahl.

Ingalls would be right at home with "The Jungle Lodge," the tale of two young American sisters on a tacky, touristy Amazon expedition. Abby and Liz find themselves mysteriously smitten with a macho native guide named Carlos, who can "turn the charm on and off with the mechanical regularity of a traffic light." Abby, unnerved by the barely tamed wildness of the rain forest, eventually learns from Carlos exactly how wild the jungle can be; but in the last pages, she finds out that the savageness of the Amazon isn't too different from her sheltered life back home.

Funnier, but no less revelatory, is "The Secret Spot," in which Helen, a suburban mother out for a day in Central Park, comes across Julia, the woman with whom her husband had had an affair years before. Helen has spent years rehearsing this moment, and her attempts to rub Julia's nose in the shiny happy details of her suburban life are hilarious in their Napoleonic strategy. Dark telegraphs the twist in their tale early on, but it's pure misdirection; when the real tangle in this triangle emerges, the truth is at once more mundane and infinitely more upsetting than Helen ever imagined.

"Dreadful Language" ties all of Dark's themes together in the tale of Frannie, an 8-year-old who achieves catharsis after her parents separate by running along the beach and screaming a foul word at the horizon, though she's not sure what it means. As Frannie matures, she never quite loses that pre-adolescent contempt, either for her mother, who remarries for security, or her mother's flamboyant friend Lena, who marries for money. It's only as an adult that Frannie realizes that their lives and emotions are as complex as her own, and that there are words far worse than common expletives.

Without using pyrotechnics or tricks, Alice Elliott Dark is carving out a certain territory as her own. Dissimilar as these tales are, read together they take on the feel of a fugue: What used to be, what could have been, and how did I get here anyway? Dark doesn't have the answers any more than her characters do, but their struggles and her pitch-perfect prose make for fine reading.

Kevin Allman, an Edgar Award nominee for his novel "Tight Shot" and editor of the magazine WHERE New Orleans.