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the perception of Per Se as one of the country’s great restaurants, which I shared after visits in the past, appear out of date.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.