Mandarin Plaid

S. J. Rozan, Author St. Martin's Press $22.95 (0p) ISBN 978-0-312-14674-0

Rozan (Concourse, 1995) puts a unique spin on her mysteries that plumb New York City's Chinese-American milieu and feature petite PI Lydia Chin and her tough sometimes-partner, Bill Smith. Lydia's brother Andrew recommends her to rising fashion designer Genna Jing, whose sketches for her exclusive debut collection, ""Mandarin Plaid,"" have been stolen. Genna hires Lydia to deliver the ransom demanded for the drawings; as Lydia makes the drop, someone shoots at her; in the ensuing turmoil the money disappears. Genna suspects her former fashion-show producer, Wayne Lewis, is behind the theft; but when Lydia and Bill go to interview him, they learn he's been murdered. Genna's boyfriend, John Ryan, fires Lydia and Bill. Suspicious of his motives, they begin their own investigation, which leads into the dark underside of fashion modeling, rife with drug addiction and prostitution. Although the plot is made murky by too many red herrings, Rozan, as usual, creates a fully realized Manhattan populated with memorable characters: John Ryan's manipulative mother; Ed Everest, a pimp posing as a model's agent; Genna's elusive sister Dawn; Roland Lum, a boyhood friend of Lydia's brothers who suddenly shows interest in her; Bill's hulking police nemesis with the unforgettable name Det. Harry Krch; and Lydia's endearing mother, forever hoping for a son-in-law. (Sept.)