And what, exactly, went on tonight behind the closed doors of the Baker Street Irregulars' annual dinner at the Regency Hotel to celebrate Sherlock Holmes' 132nd birthday?

Well, John Bennett Shaw of Santa Fe, N.M., planned to present "an artifact, a life mask of Sherlock Holmes made in Grenoble, France, probably in 1894, irrefutable proof that Sherlock Holmes was alive, at least then."

And Isaac Asimov, the whiskery author, was going to sing, as he does every year, Sherlock Holmes songs, set to tunes like "Good Night Irene" and "Believe Me If All Those Endearing Young Charms."

There would be papers delivered. "Learned and humorous papers," said writer Christian Steinbrunner. "More humorous than learned." (In the past, for instance, a Sherlockian -- as these people are called -- presented evidence that Dr. Watson's war wound, which Arthur Conan Doyle absent-mindedly placed on the good doctor's arm in one story and on his leg in the next, could have been a double wound caused by the same bullet, provided Watson was in a rather odd position when struck.)

"And many, many, many toasts," Steinbrunner added.

This was the crowning event of a full weekend for the Irregulars, who had convened, many in deerstalker caps, from all over the United States. It began Friday morning with the Martha Hudson Breakfast at the Algonquin Hotel -- an occasion named for Holmes and Watson's landlady at 221b Baker Street. Then came a reception at the Mysterious Book Shop on the West Side, and this dinner for nearly 200 men.

The Irregulars have admitted only two women in the 52 years since Christopher Morley hosted the first banquet, "and both of them are smart enough not to come," said Shaw. But female Sherlock Holmes buffs, calling themselves the Adventuresses of Sherlock Holmes, were holding their own birthday dinner at a chop house across town, and most of the offshoot Sherlockian societies around the country, like The Red Circle of Washington, are coed. Asimov, who pointed out a bit defensively that except for this dinner, the Irregulars and the Adventuresses mingled throughout the weekend, noted that "Sherlock Holmes was a woman hater."

"It's really a boy's game that grown men still play," confessed H. Paul Jeffers, a writer who in one of his mysteries had Holmes collaborate with Theodore Roosevelt to solve a crime.

How does one become an Irregular? "You cannot join; you are chosen," explained New York attorney Andrew Peck, "for service to the cause." Peck's service is editing "The Commonplace Book," one of 16 Sherlockian journals published in the United States. "Commissionaire" Julian Wolff, the retired physician who runs the organization with autocratic panache, presents new members with a shilling -- the wages Holmes gave to the street urchins who were the Irregulars in the Conan Doyle stories.

Besides the shilling, the Irregulars receive a name from the canon. Asimov is The Remarkable Worm Unknown to Science. Wayne Swift, a Chevy Chase computer engineer and one of several tuxedoed Washingtonians in attendance, is The Giant Rat of the Sumatra.

"Everything Holmes did was for the right motive," said Swift, trying to explain the enduring fascination with the great detective. "Holmes cheated like hell. He was a real snob and socked it to the lower classes. But there was an essential justice and decency that appeals to everyone."

The Irregulars, almost to a man, had seen the Steven Spielberg production "Young Sherlock Holmes," and debate among them as to the movie's merits was spirited. Jon Welenberg of Alexandria, a Pentagon official and editor of the quarterly "Baker Street Miscellanea," enjoyed the film, though he found it "not wholly canonical."

" 'E.T. Meets Moriarty,' " sniffed David Skene-Melvin of Toronto.

" 'Indiana Holmes and the Temple of Doom,' " added Peck.

But Shaw, who each year at this season repairs to a saloon in Moriarty, N.M., to drink Holmes' health, had the most Irregular perspective.

"An elegant work of fiction," he pronounced it, "about a real person."