For all those girls who will grow up, euphemistically, to read Mignon Eberhart or Phyllis Whitney, this is an only slightly younger variant... or about what happens when Robin Odell leaves Iowa for San Francisco where her older sister married Jock Dulany six weeks after meeting him at the college student center. They are living with Jock's mother, a social arbiter who would give Dorothy Spreckels a run for her money, but there are indications that our cornfed girls are unwelcome; a column in the newspaper reviving Jack's interest in a former girl; one of Mrs. Dulany's jade bracelets (and she's got more than Gump's) in Robin's drawer; and finally the kidnapping of both girls. . . . Well, the mystery's not much but it's more glamorously accessorized than in her last book--if relative value judgments are to be made--and the girls will read it if you want them to.