Two worlds -- New York with an aura of restless rootlessness, in the round of brief marriages, quick divorces and remarriages which Harriet Piers accepted as the norm -- and Milan, where affairs formed an undercurrent in the social give and take, but where marriages were made to last -- this is the portrait in contrast Marcia Davenport draws. But when Harriet seeks escape in a Milan winter, in a friend's flat, rented for the winter, she was looking forward to reestablished intimacy with Lydia Marchesi, married to an Italian, to music and gaiety and forgetfulness of a brief, tasteless marriage. She wasn't bargaining on Carlo Dalverio, charmer, man-about-town, considered irresistible by a succession of women whom he had had briefly, knowing only that his marriage to Pina was founded on shared traditions, family approval, and a mating considered ideal. And then- quite without intent on either side, they fell profoundly, intoxicatingly in love. All Milan- of their shared circle- recognized it as different. Here is a ""brief encounter""- set against a luxurious background, skillfully and sensitively recorded in flawless taste- but the passionate undertone, the acceptance of physical oneness, the discord of guilt, of the inevitability of but one end, all are here. Some will feel it is an amoral book; few will think it immoral, and the end, which might have been contrived is somehow right. Marcia Davenport writes well of this international, cosmopolitan world.