I went to a party at a large embassy the other evening and saw some of my best friends, but they didn't say hello. They didn't even nod.

I was invisible.

I was a waiter.

After two or three passes with the hot hors d'oeuvres, most of them recognized me -- it takes practice not to catch a person's eye, I guess -- but two or three never did discover me.

From the other side of the table, the Washington cocktail party is pure anthropology. It's the urban American tribal dance. In fact, some say it is the best place to observe in action the class system whose existence we so hate to admit. I just thought it would be interesting to cover a party from the worker's point of view. I was right. It's better than the other way.

When I got there an hour before the guests, Brad and Jane had already taken over the kitchen to make zucchini puffs and brie en croustade : tiny cheese souffles as light as a whisper. I helped set up the two bars, and then my friend, Jerry Croce, co-owner of Lansdowne Catering who was running the show and who had agreed to hire me for the occasion, taught me how to skirt a table.

This turned out to be pinning a curtain around the drinks table in elegant ruffles. Halfway through, the Ice Crisis struck -- 20 minutes to party time and still no ice -- so Jerry rushed off and I was left to skirt a whole table myself. I thought it looked pretty good, except I had a lot of curtain left over.

When the ice arrived Jerry checked out my work. "Fine," he said, "but you forgot the sides."

Oh dear. But by that time I was busy learning how to fan the napkins, twisting stacks of square cocktail napkins into spiral piles. The kitchen was beginning to smell great. Jerry smuggled us a tumbler of wine and an imported beer, far gutsier than the road-show version.

Suddenly the embassy chauffeur popped his head around the pantry door and gave the high sign. Dramatically, Jerry announced: "The first guest has arrived!"

It took nearly an hour for the party to blossom with its hundred guests. By then, the hot goodies were coming out of the oven by the score, and everyone was working smoothly. Between passes of hors d'oeuvres, Jerry and I would make a quick round to pick up dead glasses. They always accumulated in the same places. Like the guests.

A curious scene. The huge living room, with its Oriental rug and its priceless paintings, remained empty for the whole two hours, even though that was where the main bar stood. Everybody wanted to cluster around the food in the dining room. Some types:

The shy couple. They don't know a soul, so they talk to each other with great animation in a corner.

The rock. He picks his spot and stays there throughout. Usually within reach of the food.

The great friends. There are four or five of them, and they're having a reunion, a party within a party, and you'd better not try to crash it.

The lost soul. Now in one room, now in another, now in a group, now hitting the chopped liver by himself, he always seems to be looking for something.

The star. In this case it was the Fulbrights, who hung out in the center of the room and let people find them. Some guests tried hard not to be impressed; some stuck close to listen; some chatted them up quite casually, acquiring a bit of star quality themselves.

The insiders. A couple of men in sober suits, they spent the whole evening talking to each other in a foreign tongue.

Passing food, you got to know your regulars. A staunch few took something every time. Others refused the first six tries and then, resistance fading, turned into addicts. Some only wanted the Brie. A couple would catch your eye from 20 feet away, while others would wait until you had gone by and reach out impulsively to bring you back.

The talk: It's amazing how little you need to hear to grasp an entire conversation. In this case, there was a lot of movie, excuse me, cinema, chatter.

". . . but then, Hitchcock was a mediocre director, don't you think . . . " (Another type: the cocktail party bomb-thrower.)

"But a hausfrau would do all that as a matter of course . . ." (Has there been a single party anywhere in America in the last 10 years that managed not to bring up sexism?)

". . . and that kind of foreign minister is my kind of foreign minister." (He once was introduced to a top diplomat and never got over it.)

"No, I mean it. Call me tomorrow morning at work. I'm serious, now." (There it is: the essence, the very kernel, of the Washington conversation.)

We were picking up more empties. There wasn't really much drinking, and what there was was vodka tonics and white wine. People don't drink all that much at official parties here. But the eating was another story. Brad figured he must have baked 600 rich little delicacies. He ended up with a couple dozen. And the crab claws went even faster than the hot cakes.

"This is a dull one," someone in the kitchen said, meaning the stove didn't catch fire, nobody had hysterics, no one cut their finger off. "You should see some of the crazy ones. Controlled lunacy. Like at the National Portrait Gallery, where we had no kitchen and had to work under the staircase." That was the celebrated Scott Fitzgerald party with the fountains, and the guests in period costume. People still talk about that one.

Some groups are impossible to work for Jerry commented. They give no directions, are capricious and turn hypercritical after the event. They spend a lot of money and think that entitles them to tyrannize you.

8:42. Jerry burst into the pantry. "The party's over," he announced. "The last guest just left."

Staffers still hovered around the food, but it was family now, so the pantry door was opened while the bars were dismantled, hundreds of glasses and cases of liquor were carried to the dumbwaiter, the serving dishes were washed and great mounds of food packed or thrown out.

Working with quiet efficiency against a 9 o'clock deadline (or it's overtime), the crew dismantled the bars, hustled their gear down to the van, bagged the trash, wiped the ashtrays, swabbed the floor. Their policy is to leave the place cleaner than it was when they arrived.

Word came down that the ambassador thought it all went off beautifully. The guests had a chance for some serious talk, he said. They loved the food, he said.

We strolled out into the cool night, tugging loose our bow ties. In my pocket I had a little bag of cheese puffs and a check for $35.