A new departure for Miss Seymour -- a story not in light vein and ending with a needless and somewhat sordid tragedy. The story of an American girl whom men find attractive -- for the passing moment, but who loses out in successive adventures into the fringe of romance. Hated by a shallow mother, virtually imprisoned in a French household, Mardi seizes anything that offers escape, and finds another sort of bondage in successive affairs which lead nowhere. Absorbing -- though depressing -- reading. But watch your market, and don't sell -- or rent -- on the basis of her previous books.