This slick hospital thriller has the hokey characterization typical of the genre, and lacks the factual detail that made Robin Cook's early novels convincing. But it's a surefire success because of its subjectplastic surgeryand the serial rights have been sold to Cosmopolitan . Katz, author of TV dramas (not the Bill Katz who edits Magazines for Libraries ) is a skillful suspense builder. Andre Laval, plastic surgeon of the beautiful people and a former lowlife with a reconstructed face, tries to boost his medical reputation by creating ``the face of the nineties.'' He kills the first three unfortun ates on whom he experiments. But the fourth, a writer in search of a Pulitzer Prize-winning story, gets wise and discovers what happened to the other beauties with her face. Tacky, but a circulation builder. Joyce Smothers, Monmouth Cty. Lib., Manalapan, N.J.