By Madeleine St. John

Carroll & Graf. 185 pp. $22

This lovely, haunting little novel begins with an arresting scene: two fortyish men in a car with a beautiful woman perhaps a decade their junior. They have been at a party, and the men have offered to drop the woman off on their way home. As they ride along she begins to sing the verse from the greatest of all George Gershwin's songs, "Someone to Watch Over Me": "There's a saying old, says that love is blind/ Still we're often told, seek and ye shall find . . ."

Those words, so immediately and powerfully evocative to anyone who knows and loves Gershwin's music, set the tone for the pages that follow: achingly bittersweet, bursting with longing and love and sorrow. Not merely is "A Stairway to Paradise" suffused with the sound of Gershwin--the great song is a recurrent leitmotif--but it brings to mind Francois Truffaut's splendid film "Jules and Jim," which is another suggestive story of two men, close friends, in love with the same maddeningly alluring woman.

Madeleine St. John is a British writer previously unknown to me, as presumably to all but a handful of American readers; only one of her three previous novels, "The Essence of the Thing," a nominee for (but not a winner of) the Booker Prize, has to date been published in this country. But on the evidence of "A Stairway to Paradise," she is someone to be reckoned with. She writes with grace, fluidity and emotion, yet she is economical and her pages are utterly uncluttered. The American reader will wish upon occasion that some of her more arcane Anglicisms had been cleared up for this readership, but it's cheaper for a publisher to use the original British plates than to reset the type, and the side effects of this decision are a very small price to pay for the pleasures this novel offers.

The two men are Andrew, a mathematician and academic, and Alex, a Fleet Street ("Which wasn't in Fleet Street any more") journalist. The woman is Barbara. Andrew has "just returned from ten years' teaching in the United States, and his broken American marriage," and is now trying to "pick up the threads of the old life, the old English life"; "he'd been back here for, what, three months, and he was still treading water, trying to find the ground under his feet." Alex is still married to Claire, a broadcast star of sorts, but the marriage is unhappy and is holding together only because of the children.

Barbara is "the absolutely modern, the truly contemporary woman," with skin "so smooth, so golden" and "lustrous golden-brown hair." Andrew is swept away by her as Alex drives her to the house where she lives, doing cleaning and cooking and baby-sitting for a couple of lawyers. He regards her with awe and thinks her to be beyond his reach, much as both Jules and Jim were entranced and humbled by Catherine. Yet when he clumsily approaches her, she welcomes him, finds him appealing and dear and--to his astonishment and delight--makes love to him.

What Andrew does not know is that barely a year earlier Barbara and Alex had been passionately in love. Claire had asked Barbara, whom she knew slightly, to help with the children for a few days while she went off to a conference. Barbara at first had been turned off by Alex--"so foreign, dark, remote and unpeaceful"--but he "had been starving [for love] for years, years, years" and had fallen for her. When all of a sudden she discovered that she felt the same way about him, they made love with fierce intensity, over and over again.

Alex refused, though, to end his unhappy marriage for her. He and Claire have, he says, "a modus operandi," of which "the object is to raise [the children] as peacefully and properly as we humanly can." All he can offer her is "their own secret, sacred place; one in which the sensations they shared, of torment now and not of ecstasy, seemed as endless, as boundless, as time, every hour which passed, an eternity."

So they end the affair, and go their separate ways. Then, all accidentally, the party brings them back together. Andrew, unaware of what had transpired between his friend and Barbara, pursues her; Alex, only dimly aware of what may be happening between Andrew and Barbara, decides to approach her once more. "Life is a bad dream . . ." Barbara says. "Oh, there are some good bits, but on the whole it's a bad dream where things just happen completely beyond one's control." It's all "crazy," Andrew thinks: "Will it--can it--ever come right-- really right--now?"

There are many loose ends here, but Madeleine St. John declines to tie them neatly. Instead she leaves us, at the end, to ponder the capriciousness of life and the terrible burdens the human heart must bear. She is a wise writer, and a humane one, and "A Stairway to Paradise" is a beautiful book.

Jonathan Yardley, whose e-mail address is yardley@twp.com.