By Tess Gerritsen

Ballantine. 336 pp. $24.95

Tess Gerritsen's "Vanish" is not a book I would read for pleasure, but that is not to say it lacks value.

Based on Gerritsen's record, we can safely assume the novel will be another big success, and for me its primary value lies in whatever insight it can provide into bestsellerdom today. Gerritsen's editor, in a "Dear Reader" note sent with the advance edition, advises us that "regular readers of Tess Gerritsen brace themselves for a delicious downpour of shocking surprises."

I interpret that as fair warning that plausibility and logic are not the author's strongest suits, as indeed they are not, but she has other strengths that clearly compensate as far as her fans are concerned.

The book's greatest asset is its heroine, Boston homicide detective Jane Rizzoli, who has graced previous Gerritsen novels. Rizzoli is ethnic, spunky, stubborn and, according to her husband, "honest, and brave." Despite having been called "Frog Face" in her youth and having more than her share of insecurities, she won the love of the dashing FBI agent Gabriel Dean: "Her beautiful Gabriel. How did she get so lucky? What did she do to deserve him?" To complete her happiness, Rizzoli is nine months pregnant with their first child when the story begins. Perhaps you don't have to be a woman to enjoy this book, but it helps to have a serious interest in the difficulties of childbirth and breast-feeding. In this case, the difficulties include shootouts, hostage crises and hired assassins threatening to kill mother and child.

The novel's plot centers on sex slavery. In the opening scene, some teenage girls from Eastern Europe arrive in Mexico City, thinking they have legitimate jobs, only to be driven into the desert, raped -- murdered, in one case -- and then handed over to Americans who will transport them to brothels in this country. To underscore the scope of the problem, Gerritsen has a Justice Department official declare that there are at least 50,000 "involuntary sex workers" here. Early in the novel, we meet Rizzoli's friend Maura Isles, the Boston medical examiner -- medical examiners and their gory business are yeasty ingredients in the bestseller mix -- who is aghast when one of the corpses in her "cold room" turns out to be alive. Soon enough, the corpse is reborn as a beautiful, very angry young woman who, with a confederate, kidnaps the pregnant Rizzoli and several other people. This leads to a lengthy scene that has Rizzoli's FBI agent husband pleading for negotiations while other cops are eager to charge in shooting. Meanwhile, Jane is in labor and starting to bond with her captor: "I can't believe it. A crazy woman wants to be my labor coach." The kidnapper is in fact a sex slave who has escaped and wants to tell the world of her plight but is convinced the U.S. government will kill her first.

This brings us to the most interesting element of this bestseller-to-be. Gerritsen doesn't stop with having her villains be men who traffic in and kill young women. These monsters prove to be part of an even larger, darker conspiracy that reaches to the top levels of government. A certain corporation keeps turning up in the narrative. "We're talking about a Goliath in Washington. White House buddy. The country's biggest defense contractor." We've seen young women forced to service wealthy men on a yacht, and this corporation proves to be the owner of a house where they are kept prisoner and eventually murdered. The name of the corporation is Ballentree, which to my ear sounds like Halliburton. It is notable that Gerritsen, who gives no other sign of political concerns, feels free to hint at massive evildoing by an organization so closely identified with the present administration. There must be a great many cynical or disillusioned book buyers out there.

Jane survives the hostage crisis and has her baby and soon has new problems ("pink gums clamped down like a vise on her nipple"), but she's still a cop. This leads to a rare dispute with her loving husband as he keeps reminding her that she's on maternity leave and she keeps reminding him that they have a case to solve. Solve it they do, although not without confronting killers from a shadowy federal intelligence agency, one of whom is eager to murder both Jane and her infant daughter.

"Vanish" will be popular because it gives women readers a plucky heroine to root for, puts her on the side of the angels with regard to crimes against women and tosses in a vile conspiracy involving the supposedly virtuous, flag-in-the-lapel white guys who lead us.

The novel is corny at times, and its prose was well described by a fan who said online that "Tess has a writing style that is easy on my mind." The events described often won't withstand scrutiny, but they move along briskly, and we never doubt that justice will prevail and that fearless Jane will survive with husband, daughter and marriage intact. Another sort of writer might have made this quite a dark and troubling thriller, but in Gerritsen's hands it's harmless fun, which is more than I can say for many bestsellers.