Married people meet on a train, fall in love, then part: There is a Brief Encounter feeling to this novel, despite its modernity. In the first section, the titular "London Train" is Paul's means of escaping his family in the Welsh countryside to join his pregnant daughter (by a first marriage) in the city. In "Only Children," which follows, Cora rides the train when she flees London --- and her husband --- and returns to her birthplace in Cardiff. Beyond the train itself, the comparison with that classically reticent film makes sense because of the way Hadley's prose recalls its painful delicacy and tremulous undercurrents. Her intelligence is keen; her writing is fresh and precise.

Paul is a middling author and critic living with his wife, Elise, and their two daughters. His mother has just died in a home for the elderly; on the last night of her life, she made what the institution's owner calls a "bid for freedom" --- meaning that she wandered out into the garden wearing only her nightgown. When Paul subsequently discovers that Pia, his adult daughter, is pregnant and living in a grubby London flat with a couple of Polish immigrants, he sets out to rescue her. But within days he finds himself slipping into Pia's life, dabbling in a more casual, less thwarted existence.

Loss also triggers change for Cora, a teacher married for a dozen years to Robert, an apparently unflappable civil servant considerably older than herself. Like Paul, she is an only child, and like him she has been left fretful and unmoored by her parents' deaths. Unhappily childless, torn between a desire for independence and her "old-fashioned wife-identity," she starts commuting to Wales to renovate her childhood home with a view to its eventual sale. It's not clear what triggers her separation from Robert --- we hear about it only in retrospect. But when the house is finished, instead of putting it on the market, she moves in.

Paul and Cora's stories are presented separately, so the reader can relish the gradual unearthing of the parallels --- and one actual intersection --- between their trajectories. Their respective "bids for freedom" are the obvious link. Hadley is brilliant at evoking the ambiguities of intimate life: the contradictions of parenthood and marriage; the cycles of loss, betrayal and reconciliation. But larger social/philosophical issues also make an appearance in THE LONDON TRAIN: environmental dangers, immigration policies, city vs. country, faith vs. skepticism, past glories vs. "progress."

The emphasis on Paul's intellectual life was a conscious effort, according to Hadley's afterword ("Writing The London Train"). In his section, conceived first, she challenged herself to integrate abstract ideas with storytelling. Thus, Paul's conversations with his depressed and rather marginal bachelor friend, Gerald, often have a didactic air. He tends to wax polemical about the neighboring farmer, Willis, and his modern "improvements," for example the destruction of hedgerows and aspens that are getting in the way of his tractor ("Trees are just trees," Willis says unsentimentally). As for Elise, her very profession --- finding and refurbishing junky, discarded pieces of furniture --- represents a tension between old and new, a theme that preoccupies Paul and becomes a leitmotif for the whole section.

I liked Paul's tale, yet as soon as Cora's began, I was completely hooked on her newly minted voice and unsettled state of mind: half-married, half not. Sometimes Cora loves sleeping alone, without Robert, "weightless and free"; other times, she is "scalded by her solitary nights, sodden with dreams and longing….." The same ambivalence shapes her attitude toward not having children. She grieves, yet finds that she misses motherhood more as an idea than a reality, and "in any case, the lack that had used to be savage pain was flattening into a duller wincing….." In this transitional phase, she works in a library, where she finds peace of a kind and devours undemanding books ("women's novels," a disparaging and ghettoizing term if ever there was one, though I know what she means) to avoid too much thought about the future. Then Robert, of all unlikely people --- he became, for me, the most intriguing character --- goes missing, and Cora can no longer mark time. She is forced to act.

Bisecting a novel in this fashion carries the risk that the two sections won't be equally successful. Sadly, Paul's seems to me slightly forced. Maybe it is a gender issue; his sensibility is simply drier and more cerebral than mine. But perhaps it's also because, as Hadley herself confesses, she struggled with Paul's narrative, while Cora's story "was written in a flowing single line, not reworked over and over."

Which means that "P.S.," a feature the publisher has tacked onto THE LONDON TRAIN --- including not only a description of Hadley's experience working on the novel but an autobiographical sketch; a reprinted newspaper article, "In Praise of the Present-day Novel"; and a list of her favorite books --- could be self-sabotaging. I am dubious about freighting a novel as good as this one with supplementary material. Surely it can and should stand alone.

My advice: Just climb aboard. One measure of my satisfaction is that I'm about to run off (virtually speaking) to secure copies of Hadley's previous fiction. Meanwhile, long after the well-resolved (but perhaps not final) endings the author has given Paul and Cora, THE LONDON TRAIN's images and ideas linger like dust motes in sunlight, radiant in my mind.