NEW YORK — The lady had dropped her napkin.

More accurately, she had hurled it to the floor in a fit of disillusionment, her small protest against the slow creep of mediocrity and missed cues during a four-hour dinner at Per Se that would cost the four of us close to $3,000. Some time later, a passing server picked up the napkin without pausing to see whose lap it was missing from, neatly embodying the oblivious sleepwalking that had pushed my guest to this point.

Such is Per Se’s mystique that I briefly wondered if the failure to bring her a new napkin could have been intentional. The restaurant’s identity, to the extent that it has one distinct from that of its owner and chef, Thomas Keller, is based on fastidiously minding the tiniest details. This is the place, after all, that brought in a ballet dancer to help servers slip around the tables with poise. So I had to consider the chance that the server was just making a thoughtful accommodation to a diner with a napkin allergy.

But in three meals this fall and winter, enough other things have gone awry in the kitchen and dining room to make that theory seem unlikely. Enough, also, to make the perception of Per Se as one of the country’s great restaurants, which I shared after visits in the past, appear out of date. Enough to suggest that the four-star rating it received from Sam Sifton in 2011, its most recent review in The New York Times, needs a hard look.

With each fresh review, a restaurant has to earn its stars again. In its current form and at its current price, Per Se struggled and failed to do this, ranging from respectably dull at best to disappointingly flat-footed at worst.

Dinner or lunch at this grand, hermetic, self-regarding, ungenerous restaurant brings a protracted march of many dishes. In 2004, the year Per Se opened, the price for nine courses was $150 before tax and tip; last week, it went up to $325, with service included. Eli Kaimeh, the chef de cuisine, changes the menu all the time, but he leaves a few pieces of heirloom furniture in place: the salmon tartare and crème fraîche fitted into an ice cream cone the size of a triple-A battery; the “oysters and pearls,” a savory tapioca pudding under caviar and warm oysters; the cinnamon-sugared doughnut holes with a froth-capped cup of cappuccino semifreddo; and when it’s in season, lobster poached in butter.

These dishes, all of which Keller made famous years ago at the French Laundry in Napa Valley, show his rare combination of American playfulness and rigorous finesse. One could argue that it’s a little lame that Keller is still trotting them out. The name Per Se, after all, was chosen to suggest that New York would not simply reflect California’s glory; this would be a landmark restaurant in and of itself.

My quarrel with these greatest hits, though, is that they make Per Se’s new material look random and purposeless. The classics would suffer if you changed one element. With the notable exception of some desserts that Elwyn Boyles, Anna Bolz and their pastry team elegantly wove together, I couldn’t say that about many other recent dishes.

The kitchen could improve the bacon-wrapped cylinder of quail simply by not placing it on top of a dismal green pulp of cooked romaine lettuce, crunchy and mushy at once. Draining off the gluey, oily liquid would have helped a mushroom potpie from turning into a swampy mess. I don’t know what could have saved limp, dispiriting yam dumplings, but it definitely wasn’t a lukewarm matsutake mushroom bouillon as murky and appealing as bong water.

It’s a bit of a mystery what pickled carrots, peanuts and a date wrapped in a soft crepe were supposed to do for a slab of Dorset cheese from Consider Bardwell Farm, but a good first step would have been allowing the washed-rind cow’s milk cheese to warm up to a buttery softness; served cold, it was rubbery and flavorless.

Even canonic dishes could be mangled. One time the sabayon in “oysters and pearls” had broken and separated, so fat pooled above the tapioca.

Keller wrote in “The French Laundry Cookbook” that poaching lobster in butter “cooks it so slowly and gently that the flesh remains exquisitely tender — so tender some people think it’s not completely cooked.” There was little danger of anyone’s making that mistake on two occasions when the lobster was intransigently chewy: gristle of the sea. The first time, it was served with a sugary Meyer lemon marmalade and a grainy chestnut purée that tasted like peanut butter to which something terrible had been done. Subsequently, it was paired with a slick of cold oatmeal.

Along this gravel road, there were some smooth stretches. Lubina, the European sea bass, was sheathed in handsome golden scales of potato and bewitchingly sauced with a reduction of red wine and port swirled with butter. Bulging agnolotti filled with butternut squash and mascarpone were fat envelopes of pure pleasure. The flavors and colors of roasted sunchokes, vinegared beets, peeled Concord grapes and puréed pistachios came together in vivid harmony.

The type of daring — where did that come from? — thrill that you hope to get at a restaurant like Per Se appears rarely, but it was there in a majestic pile of osetra caviar over deeply savory bonito jelly and cured fluke that had been pressed between sheets of kelp, a flavor-enhancing trick known in Japan as kobu-jime.

More familiar, but just as transporting, was the risotto, supersaturated with brown butter and creamy Castelmagno cheese. A server appeared with a wooden box and a shaver, and the plate momentarily disappeared under a rain of white truffles. A few minutes later, even more truffles poured down.

Both dishes, though, came at an extra charge: $75 more for the caviar and $175 for the risotto. The supplements at Per Se can cause indignation, among other emotions. When my server asked, “Would you like the foie gras"— $40 more — “or the salad?,” the question had an air of menace. When the salad turned out to be a pale, uncrisp fried eggplant raviolo next to droopy strips of red pepper and carrot, it felt like extortion.

Some of those prices came down slightly when the baseline cost went up. With or without supplemental charges, though, Per Se is among the worst food deals in New York.

Keller was a leader in the service-included model of pricing, although he muddies the waters by leaving a line for an optional gratuity on the check. Just what kind of service is included?

The people who work in Per Se’s dining room can be warm and gracious. They can also be oddly unaccommodating. When one of my guests didn’t like a sample of a red being offered by the glass, the sommelier decided to argue, defending his choice instead of pouring something new. When I asked to see the truffle being shaved over somebody else’s plate, it was whisked under my eyes for a nanosecond, as if the server were afraid I was going to sneeze. I know what truffles look like; what I wanted was to smell it.

Wineglasses sat empty through entire courses. Once, the table was set for dessert so haphazardly that my spoon ended up next to my water glass instead of my plate. Sitting down after a trip to the restroom, one of my guests had his chair pushed back into place with a hard shove. Has the dance teacher been replaced by a rugby coach?

Servers sometimes give you the feeling that you work for them, and your job is to feel lucky to receive whatever you get. As you leave, you’re handed a gift bag. It’s small, but still too big for its contents, two chocolate sandwich cookies for each person and an illustrated booklet called “Per Se Purveyors.” No doubt this will make useful reading some sleepless night, but it feels like the swag that’s given out after a free press lunch. Except Per Se isn’t free.

It’s possible to pass an entire meal in this no-fun house without a single unpleasant incident apart from the presentation of the check. The gas flames in the glass-walled hearth are a cheerful sight, and the view of Central Park’s tree line past Columbus’ marble head is an unbeatable urban panorama. But are they enough? Is Per Se worth the time and money?

In and of itself, no.

Per Se

(Two stars)

10 Columbus Circle (West 59th Street), Upper West Side; 212-823-9335; perseny.com

Atmosphere: A tranquil and cosseting cloister with a wall of windows overlooking Central Park.

Service: Highly variable, from gracious to unobliging.

Sound Level: Hushed.

Recommended: Choices are limited to a vegetable tasting or a chef’s tasting menu with few options.

Drinks and Wine: Cocktails and a deep, carefully considered wine list, including a useful cluster of half-bottles and scattered choices under $100.

Prices: $325 for nine-course tasting menus, with large supplemental charges for caviar, foie gras and truffle dishes. At lunch, a five-course $215 menu and a seven-course $255 menu are also offered.

Open: Friday to Sunday for lunch; daily for dinner.

Reservations: Accepted.

Wheelchair Access: The dining room and accessible restrooms are reached by an elevator.

What the Stars Mean: Ratings range from zero to four stars and reflect the reviewer’s reaction primarily to food, with ambience, service and price taken into consideration.