There are themes that staunchly cling to their inherent significance, refusing to buckle under the pressure of demystification, whether it takes the form of satire, burlesque, or parody. These themes — death is one of them, sex another — may partake of the ironic but they are, in the end, beyond the belittling purview of irony. Of the two, sex has by far the greater claim on our immediate, quickened interest.

The besetting trials and triumphant pleasures of erotic experience are attractive to every kind of writer, from novelist to aphorist (Woody Allen: “Is sex dirty? Only if it’s done right”), precisely because there is so much stretch in the material, allowing space for an infinite game of compare-and-contrast: How do other people do it? And do they like it more? Less? Pant for it? Shrink from it?

Living as we do in a time of prescribed sexual candor, we assume that what goes on between other people’s sheets isn’t hard to imagine, that we can pretty much envision what is going on over in Bedroom X and what is failing to take place in Bedroom Y. But of course, “sex and all that sort of thing,” as Somerset Maugham described it with his usual weary disdain, remains as elusive a subject as it ever was. Perhaps the signal difference between the benighted Before of the 1950s and the liberated After of the 1960s is that they knew they were fumbling their way in the dark whereas we pretend that the light has been turned on and everything is illuminated.

Ian McEwan, who has considered the perversities and distortions of sexual desire from the very beginning of his long career (in a story from his earliest book, “First Love, Last Rites” (1975), a sociopathic narrator blithely introduces his younger sister to the discreet charms of incest) has set his latest novel in 1962, a year in which the sexual climate was virtually indistinguishable from that of the repressed ’50s. “On Chesil Beach” (Nan A. Talese, 208 pages, $22) takes us back into an England of muffled urges and inedible cuisine, to a time when “the Pill was a rumor in the newspapers, a ridiculous promise, another of those tall tales about America.” It is an age when marriage generally preceded — or immediately followed — sexual intercourse and “when to be young was a social encumbrance, a mark of irrelevance, a faintly embarrassing condition for which marriage was the cure.”

We are introduced in Part I to a young couple, Edward and Florence, on their wedding night. Rather, we enter the narrative smack in the lead-up to their wedding night, as, preparatory to tying the carnal knot, they eat dinner served off a trolley by two flustered “youths in dinner jackets” in their hotel suite on the Dorset coast. The charged psychological states of both bride and bridegroom, he a promising historian, she a gifted violinist, are carefully delineated between pointillist descriptions (“Edward ate only token morsels of potato, which he carved with the edge of his fork”) and judicious amounts of period detail. The latter is expertly threaded in and, like establishing shots in a film, transports you instantly into the sensibility, the look, and the feel of a different time and place:

From downstairs they heard the wireless, the chimes of Big Ben at the start of the ten o’clock news. … The older guests would be down there in the sitting room, taking the measure of the world with their nightcaps — the hotel had a good selection of single malts — and some of the men would be filling their pipes one last time that day. Gathering around the wireless for the main bulletin was a wartime habit they would never break.

Edward, notwithstanding the “conventional first night nerves” that assail him, can’t wait to get himself and his bride hurtling forward on “the path to pleasure,” having daydreamed of this moment throughout the months of their cautious and impeded courting. During this period, he has been made exquisitely aware of Florence’s “shyness,” her tentative embraces and hasty retreats that have caused him to bide his time. All the same, he has persuaded himself that hers is no more than a “customary reticence,” a kind of leery feminine habit of response imprinted by the decade, beneath which she is raging to join him in the sack.

Poor Edward. Poor deluded, wishful Edward, who has visions of his deer-in-the-headlights bride being of a mind to “take his c— into her soft and beautiful mouth,” perhaps this very night, and who has convinced himself that Florence’s “beautiful light brown eyes” are “bright with undeniable passion,” when the more likely explanation is that they are incandescent with fear:

Her problem, she thought, was greater, deeper than straightforward physical disgust; her whole being was in revolt against a prospect of entanglement and flesh; her composure and essential happiness were about to be violated. She simply did not want to be ‘entered’ or ‘penetrated.’

The classic Victorian and Edwardian mismatches — John Ruskin and his young bride, Eppie, who scared him off conjugal relations forever when he saw her pubic hair; Leonard Woolf and the skittish Virginia, who retreated into a white marriage after one or two desultory passes at coitus — have nothing, as it will turn out, on Edward and Florence.

The first section closes with a cliff-hanger, leaving us several steps closer to the brink of consummation as Florence, “trapped in a game whose rules she could not question,” has borne up under the torment of a French kiss (“she immediately felt his tongue, tensed and strong, pushing past her teeth, like some bully shouldering his way into a room”) and then — primarily to escape the feelings the kiss has aroused in her (“pinioned and smothered, she was suffocating, she was nauseous”) — takes her eager husband by the hand and leads him toward the bedroom. In the following sections of the novel — which, slim as it is, is dramatically divided into five parts, indicating a firm authorial hand, closing and reopening the curtain — we learn about the couple’s different but equally complex backgrounds, the chanciness of their first meeting and the slow percolation of their romance. We discover as well the calamitous consequences of what actually transpires after they repair to make the beast with two backs — or, as Mr. McEwan puts it, to “lie down together on the four-poster bed and reveal themselves fully to each other.”

Mr. McEwan’s fulsomely biblical wording will, I think, give pause to anyone who is unwilling to be guided — well, pushed — into his novelistic program, which includes the use of glaringly obvious displacements from the human onto the natural landscape (“The garden vegetation rose up, sensuous and tropical in its profusion”), and a kind of leading-the-jury reliance on technical or stilted terms for sexual organs and acts, the better to make his point about the conflict between unconfined libido and an inhibited, pre-liberation inner self. To this end, Mr. McEwan makes a great deal of fuss about a lone pubic hair that springs free from under Florence’s “panties,” which Edward rocks “back and forth, stirring in the root, along the nerve of the follicle, a mere shadow of a sensation.”

Leaving aside the mind-bending pyrotechnics that are required to accommodate this implausible description — can a single pubic hair actually be “rocked”? And is it Florence or her isolated follicle that is being stirred into sensation? — there is something both absurd and icy about the clinical close-up, which verges (and, it seems to me, unintentionally) on the pornographic. Similarly, I don’t imagine that any male on this planet, today or decades ago, has ever thought of a vagina as “a naturally formed cavity,” as Edward does. Nor do I believe that your average female (certainly not your average female, circa 1962) conjures up the word “labia” when she thinks of her vagina, as Florence does.

In the “modern, forward-looking handbook” for young brides that Florence anxiously leafs through, she comes across phrases and words such as “mucous membrane” and “glans” that “almost made her gag.” Fine and well, but what is Mr. McEwan trying to tell us with this? They aren’t words that would bring visions of anticipatory excitement to any reader, not then and not now. And are young, inexperienced women any more fond of male testicles — in Florence’s mind’s eye, Edward’s are pictured as “pendulous below his engorged penis” — today than they were then? What’s so gorgeous about a pair of balls, even if you’re ardent about the man they’re attached to?

I have other qualms about where Mr. McEwan proposes to take trusting readers who are prepared to follow him — a proven expert at his trade (my vote for his best work would be “Atonement” (2001) with “Enduring Love” (1997) running a close second, but even when he’s writing onefinger exercises like “Amsterdam” (1998), he is a writer of formidable intelligence and skill) — wherever he chooses to go, whatever the goal he has in sight. The arc of his career has been such that he might be described as something of a literary chameleon, mutating from his original incarnation as a purveyor of stories and novels that were marked by casually macabre events and a hovering sense of menace — “The Cement Garden” (1978) and “The Comfort of Strangers” (1981) are both drenched in eerie atmospherics — into a writer of greater reach and more versatile effects.

But much as Mr. McEwan may keep his readers guessing about what will emerge next from his prolific pen, his prose has a recognizable rhythm. His style is a mixture of unadorned plainness that briskly moves the plot forward interspersed with sudden, lingering descriptions of the natural world (“High up was a smoky halfmoon, casting virtually no light”) and exacting images. The determined rather than talented tennis-playing of Edward’s father-in-law is summed up in the line “he could hit the occasional beefy shot from the baseline.” The unexpected use of “jigged” instead of “jiggled” in the phrase “he jigged his knee up and down as he spoke” is either vintage McEwan, or, perhaps, a vintage Britishism, and there are few writers I can think of other than John Updike who possess the same supreme attentiveness that goes into crafting a sentence such as this: “He trod on the backs of his shoes to wrench them from his feet, and snatched his socks off with quick jabs of his thumbs.”

All that being said, I balk at the contrivances of “On Chesil Beach,” in particular, at the way the author implicitly sets up the caricatured attitude of one mythologized era (abounding in sexual repression) against the other (abounding in sexual license) and expects sparks of recognition to fly. Ah yes, that’s how it was, back when emotions were tightly wound and morals even tighter. But do couples, even experienced ones, ever “reveal themselves fully to each other”? Isn’t genuine sexual intimacy the exception rather than the rule, even today, when pubescent girls are ready to offer oral sex on a dime? And hasn’t initiation into sexual intercourse ever and always been a matter of the horny leading the less horny, even in these hooking-up times?

From his first sentence, Mr. McEwan circumvents — or merely disregards — such questions, intent as he on exploring the tendril of an idea that animates this novel, which is that once upon a not-solong-time ago the resolution of the problem of virginity carried within it the burden of making or unmaking a marriage: “They were young, educated, and both virgins … and they lived in a time when a conversation about sexual difficulty was clearly impossible.”

It was Freud, I believe, who observed that the genitals are in and of themselves ugly and that only by the grace of sublimation have we come to aestheticize — and ultimately eroticize — them. This home truth from the leading deconstructionist of the amorous impulse appears never to have entered Mr. McEwan’s consciousness. He is set on tracing the contours of sexual apprehension and disgust as though they were responses that have never been taken into consideration before, at least not from a post-Age of Aquarius vantage point. Just because we insist on acting as though, starting somewhere around the mid-’60s (“Between the end of the ‘Chatterley’ ban / And the Beatles’ first LP”) we were all born into the world free of repressions or inhibitions doesn’t mean that it is so or that we even much believe it.

I would guess that the clamorous praise this novel has received from the other side of the Atlantic has something to do with the fact that Mr. McEwan is taking up the buried — or merely conveniently disavowed — notion that some of us quail before the demands of fleshly engagement, that not all of us fly free of the impediments to carnal bliss. The ghost of Philip Larkin haunts these pages, looking pinched and salacious both. It is no accident that those oft-quoted lines from Larkin’s “Annus Mirabilis” are referenced in three of the rave British reviews I have seen and that a fourth glowing endorsement cites a different phrase from that same poem. Then again, Mr. McEwan’s fiction has always trafficked in fleeting, subliminal echoes, and “On Chesil Beach” is no different, stuffed as it is with literary influences, with Jamesian renunciations, and Proustian revelations.

And yet, though I trust neither the teller nor the tale this time around, there is something about “On Chesil Beach” that rings true beyond its self-evident agendas. It has to do with the way Mr. McEwan’s acute and unflagging awareness that our secret selves have as much sway over us as our presented ones informs the last section of the novel, after everything has fallen apart. Florence has fled in horror after Edward has erupted in a volcanic burst of sexual release, “filling her navel, coating her belly, thighs, and even a portion of her chin and kneecap in tepid, viscous fluid.” The shattered remains of what was once a friendship and a tentative romance litter the tail end of the narrative, as the humiliated couple lash out at each other with wounded and wounding accusations. It is precisely at this moment that I began to root for them, wished for them to come back together, so that they might bring forth the daughter wearing a headband that Edward envisions, and so that Florence will get to have her moment of public triumph with her string quartet in Wigmore Hall, silently dedicated to the man with the original mind who sits in the middle of the third row, in seat 9C.

But fate in the form of Mr. McEwan has dictated otherwise, and neither one is able to step across the rage and shame that engulf them. Jonathan Swift’s observation that “in marriage one person is usually the dupe” sounds harsh enough. When both partners are unwittingly duped, as happens here, there is no saving them. What we are left with, at least in the realm of fiction, is a sharpening of the lens, a moment of blinding clarity. So it is that in the poignancy of their furious estrangement, in the midst of hurling insults at each other, Edward and Florence come most fully alive, stepping clear of their puppeteer’s strings and speaking directly to us, from their Before to our After.

Ms. Merkin is the author of a novel, “Enchantment,” and a collection of essays, “Dreaming of Hitler.” She is a contributing writer to the New York Times Magazine and writes the Provocateur column in Elle.