TO UNDERSTAND why the series character is the backbone of mystery fiction, you have only to consider the most famous such immortal, Sherlock Holmes, whose creator, to his dismay, found him impossible to kill off, even with the aid of the world's most nefarious archcriminal and a 200-foot drop into a raging torrent.

The public demanded that Arthur Conan Doyle resurrect Holmes in new stories, which he reluctantly did. Even the author's own mortality finally was to no avail. When there was no Conan Doyle to write Sherlock Holmes, others took up the task and still do. Readers and writers alike continue to search for such vivid figures in words, fictional personalities whose lives invite us to adventures that never end, and who, most important, can survive every onslaught of time, from generation to generation.

Most writers fail who try simply to copy Conan Doyle's crisp, muscular, deliciously dated prose and his cantering storytelling rhythms, but new incarnations do put their own stamp on this indestructible nonexistent man, no matter where they occur -- the late, great actor Jeremy Brett, for instance, defined Holmes for our time as surely as Conan Doyle did.

Among the newest and most satisfying of writers delving into the character is Laurie R. King, who had the temerity last year to attach a 15-year-old girl, Mary Russell, to the retired detective in The Bee-Keeper's Apprentice. Russell has become a more skeptical, active Watson to Holmes, and there's a new game afoot between the master and his protegee in A Monstrous Regiment of Women (St. Martin's, $22.95). This book, which will incite consternation among purists who want Holmes's misogyny to remain inviolate, finds Mary Russell attaining her majority, her family fortune, and her first stirrings of love, the last providing a strong undercurrent of uncertainty for her (and Holmes!) about future plans.

Russell is really the dominant figure of this tale, and Holmes a supporting and often absent player during the first part of the story as Russell becomes embroiled by an old school friend with the New Temple in God, an evangelistic feminist mission in inner London led by the charismatic Margery Childe. Though Regiment takes place in the mid-'20s, it feels very much like Conan Doyle's familiar gaslight era, with the plot thickening through dangerous pea-soupers out of which emerge knife-wielding louts. King has a gift for the rich, decisive detail and the narrative crispness that distinguished Conan Doyle's writing. Plus, she has credibly put a woman in the picture, with the pleasing promise of "more to follow."

A Character Named Doyle

THOUGH Sherlock Holmes himself has been transformed into everything from Jack the Ripper to a computer, the pastiche purveyors of our postmodernist age have worked another twist on the canon: put Arthur Conan Doyle himself into the story. That's what writer and director Mark Frost (co-creator of "Twin Peaks") did in his first foray into the literature of sensation, The List of 7, published to much enthusiasm in 1993. That story led the young Doyle to his inspiration for Holmes, a fictional secret operative named Jack Sparks. Their battle with Satanists featured such historical personages as Queen Victoria, Bram Stoker, and a Bavarian infant named Adolph.

The Six Messiahs (Morrow, $23) manages to fit in Teddy Roosevelt and Thomas Edison, whose recent invention, the motion picture, captures an important clue for our heroes in their assault on the dark forces gathering in the Arizona desert to bring the end of the world. Conan Doyle is the famous author here, after he's killed off Holmes at Reichenbach.

The Six Messiahs just gallops along, as did The List of 7, but it feels a bit hollow and tinny, like the amusing but soul-less re-creations of history and fantasy to be found in Disneyworld. In fact, it shows one possible devolution of the pastiche -- into a ready-made exploitable property of the sort that entertainment conglomerates love. If not a personalized fantasia on a theme, the pastiche may easily become no more than a part of that distressing trend, the theme-parking of the novel and of arts and of playtime in general. The Six Messiahs, for all its surface pleasures, has just such a mechanical and sanitized aura to it. It's not the sort of book where you come to the final sentence with a great sigh of satisfaction and a desire to meet the characters again.

Guarding Houdini

IT'S AN older, slower Arthur Conan Doyle -- hearty and gallant and a vestige of another age -- who appears in Walter Satterthwait's country-house puzzle Escapade (St. Martin's, $22.95). He does not join the fun until page 100, and he has to share the stage with Harry Houdini, or the Great Man, as the magician's American assistant Phil Beaumont, who narrates the story, never stops calling him. Both great men are gathered to attend a seance held at the ancestral seat of Lord Purleigh, an aristocratic Bolshevist. The plot thickens around the scheme of a rival magician, Chin Soo, to kill Houdini, hence Beaumont's employment, nominally as secretary and driver but in fact as a one-man Pinkerton security detail.

Phil observes the assembled egos at Maplewhite, a massive and supposedly haunted pile in the Devon countryside, with brusque wit and a jaundiced eye. Any resemblance to Nero Wolfe's legman Archie Goodwin can hardly be coincidental. Poor Phil has an unfortunate penchant for the over-boiled simile, such as a car body "as sleek and as promising and as dangerous as a banker's second wife," but Satterthwait fills most of Escapade's pages with much more deft drollery.

The pastiche thing lends itself to name-dropping, and besides Conan Doyle and Houdini, Satterthwait works in the fictional Rebecca de Winter (the unseen title character around whom Daphne DuMaurier's famous novel Rebecca revolves), who is mentioned at the dinner table as the source of some gossip about a ghost. Everyone comes under suspicion when it is revealed that Chin Soo is a master of disguise. The aging Doyle, deeply into spiritualism by the time this story takes place, takes a major hand in solving the mystery. Satterthwait, who has a knack for poking affectionate fun at celebrities such as Houdini, treats Doyle with a tender respect that is far more touching than the fawning fandom he so often receives.

Sherlock or Solar?

ARTHUR Conan Doyle has been the most sincerely flattered of writers, to judge by his imitators, both acknowledged and unacknowledged. One who actually petitioned Conan Doyle for permission was the British fantasist August Derleth. He meticulously copied out the style in new adventures of Holmes (you can read one from 1946 in an excellent pastiche collection called The Game Is Afoot, edited by Marvin Kaye and available in paperback from St. Martin's, $13.95). Then Derleth merely changed the names for his own pair of London sleuths, the formidable Solar Pons and Dr. Lyndon Parker, who admiringly recounts his friend's prodigious feats of detection. After Derleth died in 1971, his friend Basil Copper took up the characters and penned several collections of novellas. The latest addition to the Copper stories is The Recollections of Solar Pons (Fedogan & Bremer, $25), and it includes three new tales and one restored from earlier, heavily edited American editions.

Elaborately plotted light entertainments that adhere strictly to Holmesian standards, these four adventures find the lean and exacting Solar Pons at 7B Praed Street, where he tents his fingers just like Holmes and ponders cases such as "The Adventure of the Singular Sandwich" and "The Adventure of the Hound of Hell" (which is closer kin to the Maltese Falcon than to the Hound of the Baskervilles).

Private Eyes of Color

NO MATTER where you look in the annals of mystery fiction, you will find the influence of Arthur Conan Doyle and traces of Holmes and Watson. In Spooks, Spies, and Private Eyes: Black Mystery, Crime, and Suspense Fiction of the 20th Century (Doubleday, $22.95), editor Paula L. Woods finds an African-American example in Rudolf Fisher's The Conjure-Man Dies: A Mystery Tale of Dark Harlem, which appeared in 1932. Fisher is better known for his contributions to the Harlem Renaissance (Langston Hughes called him its wittiest writer, notes Woods). But in this novel, excerpted in a remarkable and entertaining collection, Fisher became, Woods claims, the first African American to create a black sleuthing team: "tall, slender, light-skinned" Dr. John Archer and his "generously pigmented" friend, wiry and alert police detective Perry Dart. Archer is the thinking machine of this pair, observant, self-possessed and evidently more than a match for the murderer of Frimbo, the fortuneteller on Harlem's 130th Street (we don't find out whodunit, since the excerpt teasingly stops after the examination of the body).

Woods includes an even earlier mystery story, a locked-room problem called "Talma Gordon," by the prolific writer Pauline E. Hopkins, and other crime tales by more familiar writers, such as Richard Wright and Chester Himes. Sam Greenlea's sardonic thriller The Spook Who Sat by the Door is excerpted, as well as John A. Williams's harrowing The Man Who Cried I Am (Woods chooses a section about the infamous King Alfred Plan, a fictional government scheme for coping with a "Minority Emergency").

Current African-American practitioners of the mystery are represented by Walter Mosley, who wrote a new story for this collection that is not about Easy Rawlins, and by Gar Anthony Haywood, Barbara Neely, and others whose work all too briefly and tantalizingly shows the varied ways that writers have used the detective to burrow under the surface of life, solving not only three-pipe problems but deeper mysteries of the individual and society. Woods even offers up the future: a chapter from an unpublished first novel by Aya de Leon recounts a funny, vivid anecdote about a young woman's first week as a private eye in Oakland. She has troubles Arthur Conan Doyle could never imagine. The excerpt is titled "Tell Me More," which is exactly what I thought when I finished it.

Pat Dowell writes about mysteries and movies.