People begin to see that something more goes into the completion of a fine murder than two blockheads to kill and be killed, a knife, a purse and a dark lane. Design, gentlemen, grouping, light and shade, poetry, sentiment, are now deemed indispensible to attempts of this nature. Murder Considered as One of the Fine Arts" Thomas de Quincey, 1827.

One of America's more celebrated "murders" took place in a rambling, Victorian hotel near New Paltz, N.Y.

The body of the victim, identified as Avaricia Snit, bookstore owner, was found hidden in a huge bronze urn.

The discovery was made by Nancy Drew, the same gosh-and-by-golly Nancy who recently celebrated her 18th birthday for the 50th time. Having opened the case, Nancy then retired from the scene, leaving behind a deliciously complicated mystery with suspects.

Broker Buchs, IV, publisher and drunk, whose peculiar divorce settlement required him to pay $10,000 per month to his estranged wife in the event her bookstore failed.

Charisma Buchs, the estranged wife and owner of Murder Agnst, bookstore competing with Avaricia's.

Bette Noir, illegal Canadian immigrant and slave in Avaricia's bookstore.

Red Tape. bungling post office executive, one in love with Avaricia and now scheming to marry Noir.

Sue Toret, one-time law partner of Carson Drew, now disbarred for reasons known to Avaricia.

Sherill Koames, struggling author of books on detective fiction, being blackmailed by Avaricia.

So began the fifth annual Ides of Mohonk weekend (it was held at the Mohonk Mountain House), a three-day live-in clue game for fans of detective fiction. Three hundred guests spent hours questioning suspects, examining the scene of the crime and working out elaborate reconstructions of the murder. tThere were 21 teams of sleuths in all, each named for a famous detective.

To figure out what actually happened was far from an easy matter, partly because the scene of the crime was littered with red herrings (including a plastic red berring on the victim's dresser), and partly because of the inevitable confusion between the stylized facts of the imaginary murder and the humdrum of life.

"Did you see that fly on the windowsill?"

"Yes, Maybe it just happened to be there."

"Are you kidding? I can't believe that there could be a dead fly on that windowsill if the wind was blowing as strong as Red Tape said it was when he tried to ditch the mailbag. The fly means something."

The mastermind beind the entire affair was Carol Brener, owner of Murder Ink, the mystery bookstore in New York City. She made Snit a disagreeable character and created six suspects with reasons to kill her.

This weekend was organized on more or less the same principle as a short Caribbean cruise. There was an organized event to account for almost every waking moment, and guest were given the opportunity to eat five times a day.

Set on what is used to be the southermost glacial lake in the United States, the Mohonk Mountain House is isolated in a private preserve several miles from New Paltz. In an era of Holiday Inns, it is a fading anachronism, a jumble of porches, porticoes and neo-Gothic stone parapets.

It was the site of the Lake Mohonk Peace Conference of 1915, a noble but futile gesture at ending World War I. In one of the hotel's many sitting rooms, there is a fading photograph of the delegates, including Gen. Leonard Wood, Senator La Fontaine of Belguim and Charles W. Eliot, president of Harvard. They are spread out in a stiff, formal pose across the lawn, in just about the spot where they could form a welcoming committee for new arrivals.

Last weekend's guests were also treated to a stream of lectures about all aspect of sleuthing.

Handwriting expert Ina Saltz (a.k.a. Bette Noir) spelled out the a-b-c's of forgery, recounting her early duplicating New York City subway tokens in a high-school shop class.

Carolyn Fiske, an employee at the hotel, told about the poisonous properties of common plants.

Isaac Asimov tried to bridge the gap between science and detective fiction by arguing that nature is full of mysteries. According to Dr. Asimov the greatest phrase in life is "Hey, that's funny." In the spirit of that comment, he devoted the rest of his talk to an attempt to explain the disappearance of the dinosaur.

Robert Parker, author of the Spenser" detective series, gave a personal account of his approach to writing and his close identification with his fictional hero.

Satirist Solomon Hastings, renowned among mystery buffs for his analysis of how to break into a Fifth Avenue jewel shop, lectured on the intricacies of English country life. "The first illustration of cricket being played was in 1230 in a letter to Pope Gregory IX . . . "

Apiarist Karl Beard spoke at length about the poisonous effect of different varieties of bee venom.

There was late-night showings of some of the better grade-B detective movies. Edna May Oliver starred as Hiklegard Winters in the 1933 production of "The Penguin Pool Murder." Robert Young appeared in the late '30-whodunit "Miracles for Sale." In the first reel of the movie, a twittery blond interrupts him at his table in a New York nightclub. She falls over herself trying to sit down. He smiles sweetly and says: "Drink this coffee and relax."

Also on the program, along with "Laura," which gave Vincent Price his start, was the classic, "The Kennel Murder Case," starring William Powell as Philo Vance and Mary Astor as Hilda Lake. It was voted one of the three greatest detective films ever made.

The guests were a highly educated group, a lot of professionals, and no strangers to bad taste. Most seemed to enjoy themselves, enough to have kept coming back over the years. They were even observant enough as detectives to have formed impressions of one another from mysteries on previous years.

"See that fellow in the pink shirt? He's very smart. I think he wrote a mystery. A lot of these people are advertising people. They come up with ingenious solutions. There's a man, reads cryptograms. He's brillaint."

An outside observers, seeing the whole group together, would have had the impression that someone had cobbled together a joint function of a Westchester Federated Women's Club and a Mensa group. A smattering of the crowd looked as if it had come directly from Regine's on Park Avenue.

Almost without exception, the attendees were fans of the classical, British-variety detective tale, with the emphasis on detection. A genteel, amateur sleuth finds a body in a locked room. The victim had been shot. It looked like suicide. But the corner said he died of drowning, and there's not even a fish tank on the premises. Who did it?

The classical detective figures it out. Like Sherlock Holmes, he can deduce an entire biography of Watson's brother simply by glancing at his pocket watch. The classical detective, unlike the grubby, hard-boiled shoot-'em-up hero of conventional police drama, restores order to a disordered world.

Jeanne Thelwell, a New York lawyer, put it this way: "Mysteries are about taking an orderly situation, an orderly society, no matter how small that society is, a county-house weekend or a whole city. Then somebody breaks that order. And the process of the mystery is the detective, whoever that may be, attempting to re-establish order in the system by finding the transgressor and answering the questions."

It is perhaps for that reason that Marxist critics have dismissed classical detective fiction as the "the dramatization of the ideology of bourgeois rationalism."

But Thelwell has an answer:

"So what."

British author Patricia Moyes told the group that the great virtue of the mystery novel is precisely that it does help define order in a disorderly world. She quoted C.P. Snow in predicting that in ages to come, people would gain more knowledge about what life was really like in our time from Emma Latham mysteries than from conventional novels.

The virtue of mysteries, she claimed, is that they are stories "with a beginning, a middle and an end."

Precisely as planned, the murderer was brought to light and the mystery revealed, shortly after 11 a.m. last Sunday. The team that came closest to the right answer, an affinitive group of men in dinner jackets and women in designer dresses, was disqualified under suspicion of having stolen the J. Fred Skinner Memorial Rainbow Trout from the parlor.

By the way, Koames did it. Avaricia had discovered that he plagiarized a book on Sherlock Holmes. When she threatened to spoil a new book contract, he bashed her over the head with his portable typewriter.