Mystery Changes, Christie Is Eternal : Books: Crime fiction has evolved, and so has the way devotees look at Dame Agatha, still queen of the genre.

Bouchercon, the annual ingathering of mystery readers and writers, was held here on Sherlock Holmes’ turf, outside the United States for the first time in its 21-year history. Founded in Santa Monica in 1969, the event is named for the late critic and crime writer Anthony Boucher.

Over the proceedings held in King’s College on The Strand hung the ghostly but inspirational spirit of Dame Agatha Christie, whose centenary had been celebrated at Torquay, her home, a few days before Bouchercon began. Those celebrations included a special London-to-Torquay excursion aboard the Orient Express, a train naturally sacred to the memory of Christie.

Christie’s popularity continues to be phenomenal. She is outsold by the Bible but by no other single author except possibly Shakespeare, who had a long head start. She has been translated into at least 63 foreign languages, and one estimate puts the number at 103 (which might have to include sand-painting).

Tony Marks, a family friend who produced the centenary observances, said that her 78 crime novels and other books have by now sold some 2 billion copies and continue to sell at a rate conservatively estimated at 3 million a year.

“The Mousetrap,” a phenomenon within the larger Christie phenomenon, has been running theatrically in London for 38 years and still attracts large audiences. (Richard Attenborough and his wife, Sheila, who were both in the original cast of “The Mousetrap,” are still receiving modest royalties from it.) In all, the royalties to Christie’s estate from all sources amount to something like 5 million, or close to $10 million annually.

The question, explored at a panel discussion and in special articles written for Bouchercon, is how to explain Christie’s popularity, unrivaled in size and durability. For a time it was fashionable to dismiss all aspects of her writing except her undeniable and unequalled skill at setting ingenious puzzles. Her characters, it was said, were stick figures and the settings cardboard.

Latterly, there are evidences of an upwardly revisionist view of Christie’s work. Even in their economical and idealized way, her settings in the ‘20s, ‘30s and ‘40s are glimpses of social history and, not always flatteringly, of social attitudes among the upper middle classes into which she was born.

Robert Barnard, himself a first-rate mystery writer, said in an article for the Bouchercon program: “She is not a realistic writer--rather a constructor of elegant pieces of artifice--but the total picture of English life that emerges from her books, of a divided, repressed, uneasy society that finds love or gaiety hard to cope with, is recognizable and acute. And at times there are suggestions--never more, for she sketches character rather than analyzes it--of something deeper, sicker, nastier, as in the aristocratic characters in ‘Lord Edgeware Dies.’ ”

As for the put-downs of Christie’s work, Barnard quotes George Bernard Shaw, responding to similar put-downs of Oscar Wilde. “As far as I can ascertain,” Shaw said, “I am the only person in London who can not sit down and write an Oscar Wilde play at will.”

King’s College, where the Bouchercon sessions were held in windowless classrooms, did not appear to have been dusted since the reign of Queen Charlotte and was less than ideal. Visiting attendees were quartered in various locations in London, so a rousing Saturday night banquet was the sole commingling of the whole group.

But a three-day series of frequently engrossing panel discussions and public interviews (of guests of honor P.D. James and Santa Barbara’s Sue Grafton) confirmed how much the mystery form had evolved since the days of King Arthur Conan Doyle and Queen Agatha.

One panel (“Move Over Marlowe; It’s a Woman’s World”) featured, among others, Marcia Muller, whose Sharon McCone was one of the earliest of the new generation of female private eyes. (She’s actually an investigator for a small, cooperative San Francisco law firm.)

Jerry Kennealy, a working San Francisco private eye who also writes about a working San Francisco private eye, joined a panel to discuss “Mean Streets in the ‘90s,” the post-Chandler novel seen from the male side. What seemed clear was that the streets are not less mean but that the operatives have grown more compassionate, less boozy, the side-of-the-mouth wisecracks fewer except in moments of high stress.

Humor has become increasingly important in crime writing, and there was a delightful panel subtitled “The Art of Deceptive Drollery,” moderated by Simon Brett, himself one of the funniest crime writers around, and featuring, among others, Sharon McCrumb, a Virginia writer (“The Windsor Knot”). “I keep trying to be P.D. James,” McCrumb said. “But I have a smart mouth.”

True mystery-making is all sleight of hand. And, the panelists agreed, there’s nothing like a laugh for slipping a clue past the most observant reader.

The new and notably active Sisters in Crime organization evidently focused its attentions on the balloting for Bouchercon’s Anthony Awards. All 18 nominations in the top four categories turned out to be books by women. The prize for best mystery went to the London barrister-turned-mystery-writer Sarah Caudwell for her “The Sirens Sang of Murder,” a nice puzzle, just out in paperback here, set amid the intricacies of tax law.

Next year’s Bouchercon will be in Pasadena, where complaints have already arisen that too little platform attention has been allotted women writers. It just may be a lively get-together.