QUEST By Richard Ben Sapir Dutton. 390 pp. $18.95

This is escape fiction, to be sure, but of a very high order. The action takes place now, and mainly in New York City, but there's also an effortless and effective flashing back through the ages. There are scenes in 16th-century England, for example, when the huge, bejeweled saltcellar (it is more than three feet high and weighs 60 pounds) around which the plot swirls is made. But the story keeps rolling back: to the Kingdom of Toledo, 1059; then the Village of Chi, A.D. 69; then the Zascar Region, 600 B.C., as the author gives us a wealth of detail about the power and magic of rare stones. We also get an insider's look at the gem trade -- a sort of throwback to the days when suspense fiction was also expected to teach us something esoteric. It is not unwelcome.

But this is also a coming-of-age book for heroine Claire Andrews, who, in these pages, learns her own competence. At the book's start, she doesn't even travel alone ("except driving to Columbus or around Carney"), though she is 28. "The Andrewses had tried sending her to Radcliffe, but instead she chose Ohio State so she could come home weekends." In the end, she doesn't balk at taking on whole governments.

Claire remembers seeing the saltcellar in the family basement back home. She'd called it, as her father had, by the nickname "Lucky." Lucky is anything but, with a number of gruesome torture-murders accruing to its pursuit. Seems the cellar was originally presented to Queen Elizabeth I after the defeat of the Spanish Armada. Seems, too, that the Holy Grail was incorporated into its design, and that according to legend Britain will prosper as long as the saltcellar is in the possession of the sovereign. So the British want it back, badly, so badly as to send secret agents after it. But art thieves want it, too, and the chase is on.

Claire isn't put off by this, though detective Artie Modelstein from Fraud/Jewels is. At one point, trying to persuade her to let go of the artifact, Modelstein shouts, "Lady, I am a {expletive} New York City cop. You are a {expletive} ... a {expletive} Ohio person." Modelstein is attracted to Claire, but against his better judgment, which tells him that his present girlfriend, Trudy, is the wiser choice. Listen to Modelstein as he juxtaposes the two: Claire "was oblivious to danger and odds. This was not someone to be entangled with. She was not his kind. Trudy was his kind. Trudy understood the world was not a safe and good place."

Also on the trail is Capt. Harry Rawson, who gets involved when the job is botched. "Never should have trusted the Foreign Office chaps," Rawson's superior confides. "Bunch of pensioners. Might as well be French." Similarly, Rawson, a member of Her Majesty's Royal Argyle Sutherlanders, operates without "trusting the Scotland Yard sort" with the saltcellar's secret. But others are tracking the priceless piece, too, including curmudgeonly ruby dealer Norman Feldman. The characters are a wonderful lot, wildly different from one another, and all convincingly drawn. The roles that they play are solid and nicely intertwined. The author knows these folks and never makes a misstep regarding them. Even minor characters are brought into play.

The author's writing style gets high marks as well, particularly his sophisticated sense of humor. Of the aforementioned Trudy, for instance, he has detective Modelstein conclude, "Trudy was the one he should get entangled with if he wanted to be entangled. Reliable, only moderately bitchy, and usually deceivable on important matters." The author also has a great way with similes. My favorite was: "The woman's voice was British as a cold shower." But there are many more. Serious matters, too, are given ample and yet understated play. Of Rawson we learn "that in the thirty-fifth year of his life he had learned in little painful ways to believe in nothing."

The biggest plus of all, however, is the book's deucedly clever plot. It's complicated, and yet we follow it with ease. What is more, everything the author has planted keeps paying off, right until the very last page.

The reviewer's latest suspense novel, "Patchwork," was recently released in paperback.