By the author of several pop-psych thrillers, here is a no-frills suspense ordeal with a hasty dab or two of inklings about hostage psychology: a tale, in short, about a suburban housewife's scary days and nights after she and her two small children are kidnapped by a homicidal psychopath and his short-lived partner. Kate Armstrong, mother of Darran, 4, and Candy, 6, has the taken-for-granted housewive's blues; and she resents husband Ted's leaving for Chicago on a business trip. (Will he be carrying on with another woman while he's away? Yep.) Kate thinks that to the family she's just a ""hair-brained blabbermouth."" In a way they're right, for after trailing her tots through the local mall's Circus Day gala, she blabbers away to a young man under the dripping marquee of the mall--giving him all the info he needs to locate a getaway ear and a driver. The family pile into the car at gunpoint and Kate is the chauffeur for young Lowell and big Torrey on the way to Vermont. The nightmare trip goes on and on: terrified children, barked threats, grueling hours at the wheel, and finally a ruined barn in Vermont. Once in a while Kate will attempt to tune in on the lethal creep's wavelength, plow for hints of childhood troubles and hope for an escape lever: ""We both need to feel that we matter,"" she explains to psycho Lowell. ""You've been stepped on and so have I."" No go. There are a gun duel (X out one partner), Lowell's aborted impulses to kill the children, a sexual assault on Kate (who evades Lowell in-the-nick), a final shoot-out, and rescue. There's an intrinsic suspense here in the mile-by-mile trek and camp-out in the company of a dangerous thug with an itchy trigger finger, but neither the musings about hostage psychology nor the characters have much acuity or depth, and the reader won't get any closer to Lowell than does Kate.