Coming Apart : SEPARATION, <i> By Dan Franck</i> . <i> Translated from French by Jon Rothschild (Alfred A. Knopf: $19; 227 pp.)</i>

Two fashionably turned-out Parisian intellectuals bend forward in a contortion enforced by the wooden benches of the Bouffes du Nord theater. They are watching “The Tempest,” ostensibly, but for the husband “the nub of the drama has shifted elsewhere.”

An all-but-imperceptible vibration has been switched off beside him. The stillness is as shattering as the suddenly stopped breath of a dying patient. His wife, who normally is all nudges, expressive hums and sideways glances, is inert as day-old flounder. He reaches for her hand; it lies there. He reaches again; it still lies there. Body language goes dead, and so, in this cold, abstract and increasingly gripping novel, does the 7-year-old marriage.

Recently, Michiko Kakutani wrote of the geometry of moves and emotions in Francine Prose’s short stories about broken relationships. By comparison with Dan Franck’s geometry, Prose’s is furred and cuddly. Franck’s young couple are given no names; their two little children are simply “First Child” and “Baby.” Their friends, with whom they spin the spider web of opinions in which they all live and hunt, are arbitrary initials: G, Y, X and so on. Precisely, in fact, as a geometrical problem is laid out.

When Euclid brought off his bell-ringer about the square of the hypotenuse, he didn’t try for a memorable or haunting hypotenuse. Any old slant-line would do. Franck makes his characters almost featureless, and when a feature does show through, it is commonplace. The husband, whose story this mainly is, speaks modish cliches when he tries to talk about anything that does not immediately concern the agonizing struggle of two people coming apart.

Franck has made him a film writer and novelist (what else?) who zips around Paris on a motorcycle. Formerly his wife would lie against his back, bury her face in his shoulders and warm her hands in his pockets. Now she sits at one stiff inch of separation, except for the points of necessary support. He doesn’t need to describe their clothes, though he tells us she shops at designer-house sales: We are certain he sports draped leather-jackets and a Hermes shoulder bag, and that their apartment is all white walls and modern furniture.

“They were children of May, 1968,” the husband tells us, describing their circle. Now they send money to the Kurds, drink sound but middle-priced wine, rent a safe-deposit box--”tokens of their membership in the affluent class to which the radical intellectuals of Paris belonged.”

How pompous, how obvious, how formulaic. Deliberately or perhaps not--Franck is a fledgling novelist; “Separation” won the Prix Renaudot for first novels--the author has taken several large risks. After the opening scene at the theater, with its hairline cracks that presage an earthquake, the book wanders for a while. The earthquake takes its time, and the tiny cracks are worked on with some repetitiousness. Meanwhile, the abstract impalpability of the characters and, worse, their fatuousness when they come intermittently into view, test the reader’s patience.

It is a test worth passing, though. The abstraction serves a purpose. “Separation” is a very precisely delineated slice not of life but of life’s pain. It is the man’s slice but because he remains insubstantial, even as his pain becomes more and more real and affecting, we are always aware of the all-but-unspoken reality of the woman and her own pain.

It takes 135 days from the dead space at the theater to the final, disastrous separation; from time to time we get a reading on the ticking meter: 30 days, 40 days, 90 days. At first it is the wife’s silences and withholdings. At home she is polite, even affectionate, but a glass curtain has rung down. When he kisses her, her eyes remain open; when he makes love she endures it. There are no more affectionate nicknames, only a plain “you.” When she puts the children to bed she no longer calls for him to come in and take over. Instead, she stands outside their door and gestures that it is his turn; as if, he tells us, she were vacating a public toilet for the next user.

He asks what is wrong. Nothing, she says. He asks if she has a lover. Why does he think that? she parries. The days go by; she admits she has fallen in love but has not made love. Later, she will stay out all night and come back, glowing, to report that she has slept with the other man. It will happen again, this time with an announcement in advance. The affair goes bumpily--two nights, it seems, is all there are, though we get no details. With pain, though calmly at first, they talk about separating. She expects to move in with her lover, it never happens and the affair breaks off. But she will not come back to him. With increasing bitterness the rift widens; at the end, after coming to various contradictory arrrangments, she will have both children and the apartment, and he will live alone.

In a sense the initiative, even the fault, is hers; in a sense, as he complains near the end, she has won and he has lost. But “Separation” is not about fault or about winning and losing. In fact, to the extent that the breakup had a cause it lies in something more ambiguous than the wife’s virtually abortive affair. “I’m sick of living alongside a man. What I want is to live with him,” she bursts out at one point. As for her victory, he has his shiny career and she has a place to live, the children and what he calls, as he bounces off after the split for a Trouville weekend, “lugubrious Saturdays.”

What makes “Separation” remarkable is the portrait of a man floundering among love, pain, generosity and rage. As his marriage dissolves from under him, the narrator reads signals and misreads them. He rushes about to repair the holes in the fabric even as his boots make larger holes. He tries to get his wife to define herself, not realizing that, for her, definition may be strangulation. You don’t show your cards if the other person has most of them. The narrator never quite admits that he does. Touchingly, exasperatingly, he keeps inventing solutions. He will be forceful, he will be patient, he will be understanding, he will storm out, he will take everything, he will be magnanimous.

His anguish is awful. But Franck has not written a tragedy. Without our quite realizing it, perhaps, he has given us something more like comedy. It is the comedy of pain, and it gives his book its distinctiveness. The narrator’s lurches of hope and dismay, his instant illuminations guttering in a fog of misperception, build up a momentum, a precision and a savagery worthy of a Feydeau farce.