Here-and-now speculative yarn involving chaos theory and statistical prediction, from the author of the fine Doomsday Book (1992), etc. Employed by the HiTek company, Sandra Foster is trying to develop a theory that can predict how and why fads and trends begin. But her attempts to computerize her data (mostly in the form of magazine and newspaper clippings) are constantly frustrated by the awful Flip, the erratic, forgetful, careless interdepartmental assistant. Still, Flip does lead Sandra to meet biologist Bennett O'Reilly, who thinks he's discovered a hidden factor within current chaos theories. As Flip blunders about--ghastly black lipstick, weird clothes, faddish accessories, attitude problem and all-- Sandra and Bennett decide to set up a joint project to test their ideas on the behavior of a flock of sheep. HiTek's management heartily approves--such a project might well win the coveted Niebnitz Grant. Sandra and Bennett learn that a bellwether sheep unconsciously acts as a catalyst to determine the entire flock's behavior. Bingo! Flip, while seeming totally incompetent, unknowingly acts as a human bellwether, causing fads and trends to crystallize around her as she lurches chaotically through life. Willis's intriguing notion comes across with the authority of a genuine insight--and probably merits a more dramatic and thoroughgoing workout than the agreeable but bland treatment it receives here.