A Pattern of Cosmic Wrongdoing : ZADDIK, <i> By David Rosenbaum (Mysterious Press: $19.95; 438 pp.)</i>

The stone is nearly three inches in diameter, oval cut with 66 facets and a sapphire tint. Weighing in at 78 carats, it is surely a diamond as big as the Ritz and also, wouldn’t you just know it, a rock with a remarkable history.

So it should come as no surprise that the disappearance of the Seer’s Stone from New York’s West 47th Street jewelry district turns out to be no ordinary crime but rather part of a pattern of cosmic wrongdoing that has persisted over generations. Moreover, the man attempting to locate it comes to believe, its recovery just might “heal a wound that had been bleeding, uninterrupted, for 150 years.”

As this hint of its narrative strivings should make clear, “Zaddik” is considerably more ambitious than the ordinary thriller. Imagine a novel by Isaac Bashevis Singer with an ex-alcoholic detective protagonist who, much to his surprise, is able to operate within a mystical framework that allows the reception of crime tips across the boundaries of time. It’s enough to give Philip Marlowe a migraine.

Though first-time novelist David Rosenbaum can’t manage to keep all these balls in the air as dexterously as he’d like, “Zaddik” is an efficiently plotted page-turner that benefits from its involving ambience. It doesn’t take the reader into Navajo territory to witness Native American rituals, but in this secular age the world of passionately observant Hasidic Jews proves as little known and exotic as any ceremony Jim Chee or Joe Leaphorn ever participated in.

Dov Taylor, a recovering alcoholic and former NYPD detective, divorced from his wife and in desperation flirting with a return to Jewish observance, is asked by his rabbi to look into the return of the Seer’s Stone.

Bigger than the Hope Diamond and suddenly lost from view after a pair of particularly brutal murders in the jewelry district, it was meant to be the dowry when the daughter of the Satmar rebbe married the son of the Lubavitcher rebbe, a union that was to heal a long-standing rift between the two major branches of Hasidism.

These holy men naturally have little use for an assimilated Jew like Dov, considering him “some kind of mongrel,” but they tolerate his help because his great-great grandfather turns out to have been Rabbi Hirsh Leib, the zaddik or sage of Orlik. Dov for his part thinks the Hasidim, especially Rabbi Joe Teitel of Satmar, ought to be in padded cells. But when he meets the beautiful Sarah, a rabbi’s daughter with the requisite “soft, musical voice” and striking good looks, suddenly he gets more interested.

Because this thriller is not a mystery, we know almost immediately that the big diamond is particularly lusted after by an unsavory trio made up of a slippery ex-Nazi called the Magician, a top-drawer professional killer called the Cutter, and a beautiful woman named Maria, who in the spirit of things might have been called the Body but isn’t. So the story of “Zaddik” does not involve the reader in trying to solve a crime but in watching Dov gradually get a handle on the situation and deal with it.

In addition to the usual crime-stopper’s legwork, Dov comes to rely on a rather unorthodox (so to speak) technique to come to grips with the stone and its abductors. Under the influence of Rabbi Joel, he goes into a trance, enters the mind of his ancestor the zaddik of Orlik and discovers, in an intricate, 100-page excursion, that the stone was intended by the Jews of Poland to buy protection from Napoleon. Not only was Dov’s progenitor involved in that ancient story, but the ancestors of the Magician and Maria as well.

This is pretty heady stuff for a mere thriller, and Rosenbaum’s writing skills, especially his dialogue, are not always up to the challenge. Dov Taylor feels a little too derivative of Lawrence Block’s Matthew Scudder for comfort and the book’s fuzzy mysticism and pro forma excursions into sex and violence will not be to everyone’s taste.

What saves “Zaddik,” however, is its scope and how well grounded the author is in Jewish history, ritual and custom both past and present. Though the sage of Orlik is a construct and the names of the current Satmar and Lubavitcher rebbes have been slightly changed, everything else, including an extensive Hebrew/Yiddish glossary and details like the kind of clothes murdered men are buried in, seems thorough and accurate. If a book, even one that is uncertain around the edges, knows enough to mention both the Hasidic mystic Nachman of Bratslav and the preeminent Jewish historian Simon Dubnov, a certain amount of respect must be paid.