Stella Pike, sleuth-narrator of this spry yet overlong and routinely plotted novel, sees a woman thrown from a car on a California highway--but the authorities, not believing Stella's story, consider the death a suicide/accident. So Stella, implausibly motivated by curiosity (and by fear that the murderer is now after her too), does her own investigation, learning that the victim, Rosa Esposito, was involved with a shady drug-reform program and with a chic San Francisco import outfit. Soon, then, after two more deaths (Rosa's lover, a cop who believed Stella), Stella--on impetuous leave from her PR job--is infiltrating the import company and tagging along on a business trip to Peru, sure that drugs are being smuggled via Peruvian artifacts and distributed via the ""Start Over"" program. And once she gets hold of real evidence--a cocaine stash and encoded Peruvian shawls--Stella flees from assorted villains, returning to California in time to trap the bad guys and finger ""the big shark"" behind it all. This essentially familiar, simple plot (there are also guerrillas) is wearyingly belabored here; and Stella's menfolk-an ex-husband who happens to be the state prosecutor on the case, a new beau who unquestioningly follows Stella to Peru--merely add to the lack of credibility throughout. Still, Webb's scene-by-scene narration is brightly promising, and some readers may find the Peruvian scenery-with-artifacts an incentive to plow on.