A Life in Need of Flexing : DEXTERITY <i> by Douglas Bauer (Simon & Schuster: $17.95; 290 pp.) </i>

Douglas Bauer’s first novel, “Dexterity,” chronicles the aftermath of Ramona and Ed King’s three-year marriage, a union conspicuously lacking in happily-ever-after. From the threadbare fabric of their futureless working-class lives, Bauer has fashioned a finely crafted, if relentlessly grim, tale.

Ed and Ramona are natives of Myles, a decaying Upstate New York mill town where “the day was a thing of aching length.” Ed works on a highway road crew and Ramona tends their son Jonas, fighting a growing awareness that she has no particular aptitude or affinity for motherhood. In Myles, marital brutality is as much a part of life as food stamps, and Ramona’s best friend assures her that the bruises Ed inflicts during their physical arguments are proof of his love.

Bleak? You better believe it. It’s an environment that fairly screams to be left. Ramona’s even tried once, but that attempt, in her seventh month of pregnancy, resulted in a freak auto accident that severed her right hand before she even reached the town limits. True to her essential nature, Ramona then refused a functional prosthesis in favor of a passive artificial hand.

Such an experience would give even a spunky personality second thoughts about another escape attempt. In fact, when Ramona does leave again, it’s totally without premeditation. She heads off on foot across the fields with $1.67 in her pocket and no destination.

Ramona never does get more than 60 miles away, but she successfully eludes discovery. She also makes enormous progress toward an understanding of herself, first through a relationship with a tender outdoorsman, then in the assumption of a job and apartment. It is this odyssey of self-discovery, Ramona’s inching toward independence, that gives “Dexterity” its thrust and appeal.

Back in Myles, however, Ed’s a wreck. His precipitous decline begins when he dumps baby Jonas on his mother and moves into a back-yard lean-to he fashions out of old car doors. (Myles is the sort of town where old car doors are available in abundance.) A formerly slow and cautious driver, Ed takes to cruising with growing speed and recklessness.

Overnight, Ed becomes the most remarked-upon citizen of Myles, which had kept the Kings under close scrutiny ever since Ramona’s spectacularly failed first attempt to leave. “His understanding of the town was so keen because his was its quintessential mind. Had this happened to somebody else, Ed would have had more to say about it than anyone in Myles.”

Ed now has nothing to say to anybody. He fantasizes the abject return of his errant wife, refusing to accept that she might not come back. But not until he’s awarded the town’s charity turkey at Thanksgiving--a distinction reserved for the season’s most pathetic resident--does he begin to actively search for her.

Ed and Ramona are wonderfully real, created in such accurate and telling detail that the collective despair of their lives seeps from every page. Bauer has surrounded them with other characters of idiosyncratic individuality, though his most real and chilling creation may well be the town of Myles itself.